THE ISBA BULLETIN

Vol. 7 No. 4 December 2000

The official bulletin of the International Society for Bayesian Analysis

A WORDFROM already lays out all the elements mere statisticians might have THE PRESIDENT of the philosophical position anything to say to them that by Philip Dawid that he was to continue to could possibly be worth ISBA President develop and promote (to a listening to. I recently acted as [email protected] largely uncomprehending an expert witness for the audience) for the rest of his life. defence in a murder appeal, Radical Probabilism He is utterly uncompromising which revolved around a Modern Bayesianism is doing in his rejection of the realist variant of the “Prosecutor’s a wonderful job in an enormous conception that Probability is Fallacy” (the confusion of range of applied activities, somehow “out there in the world”, P (innocence|evidence) with supplying modelling, data and in his pragmatist emphasis P ('evidence|innocence)). $ analysis and inference on Subjective Probability as Contents procedures to nourish parts that something that can be measured other techniques cannot reach. and regulated by suitable ➤ ISBA Elections and Logo But Bayesianism is far more instruments (betting behaviour, ☛ Page 2 than a bag of tricks for helping or proper scoring rules). other specialists out with their What de Finetti constructed ➤ Interview with Lindley tricky problems – it is a totally was, essentially, a whole new ☛ Page 3 original way of thinking about theory of logic – in the broad ➤ New prizes the world we live in. I was sense of principles for thinking ☛ Page 5 forcibly struck by this when I and learning about how the had to deliver some brief world behaves. Its novelty lies ➤ Bayesian history comments about de Finetti at in its recognition of the essential ☛ Page 6 the meeting of the International role of uncertainty in sound Society for Clinical Biostatistics human thinking, and its ➤ Bayesians teaching in Trento last September, and provision of tools for correctly ☛ Page 10 prepared myself by reading or manipulating that uncertainty. ➤ Bayesians in Brazil rereading as much of his work Such a logic should be vital ☛ Page 12 as I could get my hands on. I importance over the whole range was particularly struck by his of human activity, not just the ➤ Applications youthful work “Probabilismo”, narrow confines of scientific ☛ Page 14 written when he was 23. An research. However, even within English translation of this the scientific community (dare I ➤ Software review (“Probabilism”) appears in a say, even within the ISBA ☛ Page 16 special issue, entirely given over community?!) there has been ➤ Students’ corner to papers on de Finetti’s little enthusiasm to listen to this ☛ Page 18 philosophy of probability, of the radical message, and it is even journal “Erkenntnis” (Volume harder to put it across to a ➤ Bibliography 31, nos. 2 – 3, 1989), which also public trained from childhood ☛ Page 21 contains a valuable overview, to regard it as wimpish ever to “Reading Probabilismo”, by admit to anything less than ➤ News from the world Richard Jeffrey. In ☛ Page 25 certainty, who can’t believe that & % “Probabilismo” de Finetti ISBA Bulletin, December 2000 ISBA

I had previously prepared a disease”) epidemic, without brilliantly served) for their deep detailed written report, which taking into account any of the contribution in shaping the was before the court. However, uncertainties involved. Slowly, “new” Newsletter. They when counsel for the defence perhaps, the ground may be deserve a hearty plause from all asked for me to be called to the becoming more receptive, and ISBA members. New Associate stand to explain my report, the the radical probabilistic seed Editors (Maria Eugenia judge replied: “We don’t really may yet take root and flourish. Castellanos and Javier Morales need to hear his testimony, do But it will need the concerted for the Students’ Corner, Kate we? It’s hardly rocket science, is efforts of all those who feel Cowles for Applications, it?”. (Clearly, he had not read proud to call themselves Duncan Fong for Bibliography, my article in the March 2000 Bayesians. Leo Knorr-Held for Software issue of the ISBA Bulletin). The and Antonio Lijoi for News final judgement pooh-poohed A WORDFROM from the World) are warming the idea that anybody could THE EDITOR up for the next issue: please get ever be taken in by the in touch with them (see their prosecutor’s fallacy, and went by Fabrizio Ruggeri e-mail addresses at on to ignore completely the ISBA Bulletin Editor www.iami.mi.cnr.it/isba ). logical points made. The appeal [email protected] Arnold Zellner is back: his was not granted. My first thought is about the new contribution is about ISBA It can be dispiriting, but we Associate and Corresponding History and all of you are must continue to try to spread Editors who are stepping down invited, as suggested by Arnold, the good word with all our from their job with this issue: to update his paper on the ISBA vigour. In Britain there has been they have been the “engine” website, www.bayesian.org. Last, but not least, a word of much public concern recently behind the success (after two thanks to Dennis Lindley, and about the way in which our years, we can say it ...) of the his interviewer (Karen Young): government solicited, used and Bulletin. I wish to thank read the interview and you will disseminated scientific advice Antonio, Gabriel, Siva and Sujit understand why! over the BSE (“mad cow (and Maria for the year she

ISBAELECTIONS to all who participated and ISBALOGO especially to those who stood as by Mike Evans candidates. The following by Mike Evans ISBA Executive Secretary individuals were elected. ISBA Executive Secretary [email protected] [email protected] ➤ President-Elect This year ISBA held an online ISBA has now chosen a new David Draper election for the positions of logo; see it at www.bayesian.org. President-Elect, Executive ➤ Executive Secretary This logo was designed by Secretary and four new Board Petros Dellaportas. members. The option of mailing Cindy Christiansen Congratulations to Petros and in the ballot was also available many thanks to all those who ➤ but the vast majority of Board Members submitted entries! We received members chose to vote online. Nicky Best 21 additional entries designed In this year’s election 147 Eduardo Gutierrez-Pe˜na by Concha Bielza, Nigel Cooper, ISBA members participated by Tony O’Hagan Jorgen Hilden, Daphne Kounali, voting for one or more of the Raquel Prado Brunero Liseo, Duncan Murdoch, positions. This participation J. Lynn Palmer, Jonathan Rougier, rate is about the same as in Juan Antonio Cano Sanchez, previous elections. Many thanks Bob Shaker and Alyson Wilson.

2 ISBA Bulletin, December 2000 INTERVIEWS

DENNIS LINDLEY again at a conference in Canada. Statistician 2000, 293-337) you say, about the Sixth by Karen Young 2. Are you aware that your procedure for Valencia Conference, that [email protected] estimation based on model ‘‘Although I was impressed estimates from that paper by the overall quality of Dennis needs no introduction is now called ‘‘Iterated the papers and the - without him Bayesian statistics Conditional Modes’’ and I substantial advances made, would not be where it is today. recently saw a paper which many participants did not compared its results with seem to me fully to 1. Dennis, you have been appreciate the Bayesian interviewed before by Gibbs sampling? Have you any comments on this? philosophy.’’ Could you Adrian Smith (Statistical amplify a bit the sort of Science, 10, 305-319) and The idea of using the modes concerns you had? we don’t want to cover the in place of the means was same ground again. One Adrian’s and I can recall him What the people at Valencia thing which I wanted to ask coming into my room one day did not realise is that Probability you about your influential with this simple and effective is the only sensible description 1972 RSS paper with Adrian. observation. I had not heard of of uncertainty. Almost Can you tell us a bit about “iterated conditional modes” everything we talk about has an its genesis? but would have expected them element of uncertainty about it to be unnecessary these days and therefore needs probability. My memory about the past is I have just begun to read not always reliable but I believe when the whole distribution can often be calculated by MCMC. Sprott’s recent book. He does the following description about not understand this for he my paper with Adrian is correct. 3. I suggested that your admits that the value of a I was enormously impressed by 1972 paper is highly parameter is uncertain and yet Stein’s proof that the sample influential and I think will not admit that it has a mean was not an admissible that it should be on the probability distribution. My estimate of the population mean reading list of any favourite example concerns of a normal distribution in research student. Can you multiple comparisons. Suppose dimensions 3 or more. suggest some other papers that we have several means that (Incidentally, this result is still which you would put on that we wish to compare. Then we ignored by many statisticians list? are uncertain of them and today. Reflect, it means that Savage did produce a reading therefore have a probability least squares estimates are list for a research student. It distribution for them. From this similarly inadmissible.) Part of appeared in American we can calculate any margin of the reason for my reaction to Statistician, 24, 23-27 (1970). The the distribution that is of Stein’s result was the fact that a two volumes by Johnson & Kotz interest. For example, we can Bayesian with a proper prior Breakthroughs in Statistics could find that of the difference would not use the sample mean, provide a good basis for a between any two of them. So so here was a result that research student. What I do multiple comparisons becomes supported this view. If you will wish is that everyone, research an exercise in the determination look up the discussion of Stein’s students and professors, would of marginals. Yet you have paper in the RSS you will find read de Finetti. I once said that whole books, for example by that I advocated a shift to the we should all take two years off Hsu, which waffle away with group mean in the case of research and read him, one year most complicated calculations one-way analysis of variance, for each volume. because they have not read de and this idea was generalised in Finetti. a paper at the London ISI 4. In a recent article meeting: Bull. Inst. Internat. on the Philosophy of 5. In that paper you Statist., 43, 152-153 (1969) and Statistics (The advocate building models as

3 ISBA Bulletin, December 2000 INTERVIEWS large as possible. That techniques of probability experiment, they experience entails specifying a big assessment, account must be Eureka moments. Unfortunately multivariate prior - do we taken of the individual’s Eureka moments are the really have any ideas how psychology, so that the problem privilege of youth; old age to do that properly? needs co-operation between rarely experiences them. I don’t know how to construct statisticians and psychologists. 7. Are you planning to a big multivariate prior but For example, it may be easier to attend Valencia and ISBA consider the construction to be answer questions about conferences and take a role the most important problem in quantiles than about moments. in the statistical statistics today, and wish people 6. During your career community in future? would spend time researching it what is it that you are I do not expect to attend any instead of working on reference most proud of and what is further statistical meetings. priors. My view is that your most memorable moment? Stress affects me adversely, likelihood and prior together Pride is one of the seven whether physical or mental (not express the scientists’ deadly sins, so I will not admit another paper on likelihood!), appreciation of the small world to it. What I see myself as so it is best to live quietly by the and the data about that world. having done is to make people sea and rely on letters, e-mail It is necessary to form this large aware of the ideas of Ramsey, and reading. probability distribution before Jeffreys, Savage and, above all, coherent inference and 8. Is there anything in de Finetti; to see that their particular you would like decision-making can proceed. concepts are fundamentally One tool that has been used to say to the ISBA sound and the only way for membership? successfully goes under various statistics to proceed, then to names, with slight differences, observe some of the There is one sense in which I but essentially directed, acyclic consequences. Rather than have always regretted the graphs. These work well if there single out a most memorable existence of ISBA, or the is enough independence in the moment, I’d prefer to identify a Valencia meetings, whilst topic. A problem I have worked class of memorable moments, recognising that they have been on, mostly without result, is a which I term Eureka occasions. highly beneficial to the prior for the dispersion matrix You have been struggling with a development of the Bayesian of a multivariate, normal problem, producing pages of paradigm. Bayesian statistics is distribution. How should we notes that make little overall not a branch of statistics, in the estimate the dispersions from sense, and you find yourself so way, say, that ’design’ is. It is a the data? Is there an equivalent immersed in the work that the way of looking at the whole of of James-Stein with means that external world almost statistics: thus there is ’Bayesian applies to the second moments? disappears; when, suddenly, all design’. We aim to interfere There is one tool in all this that falls into place and, if not the everywhere. Therefore ISBA may be important: coherence. solution, at least the road to the members’ aim should be to Consider several binary solution, is revealed. At the time abolish the section, by the quantities, x, y... One can think it appears a gigantic step section becoming statistics and of p(x = 1), p(y = 1|x = 1), forward, even if later reflection all recognise the inevitability of p(y = 1|x = 0) etc.. But equally shows that it is but a small step that attitude. Don’t just go to one could start with y, go to x, in our understanding, and the Bayesian meeting; go to in reversal of that order. The world reappears as a wonderful meetings on design and heckle. joint distributions one reaches place. Artists sometimes think “Why don’t you express your by these two routes must agree they have a near monopoly over prior opinions in the form of (cohere). There is one aspect to imagination and insight. This is probability, for those opinions this problem that is not not so, for scientists do not are all you have in design?” statistical. In devising proceed only by logic and May I share with ISBA members

4 ISBA Bulletin, December 2000 INTERVIEWS / PRIZES a quote? It comes from A Monk was true. He also was a good hero reflected a process that is and Two Peas by Robin Marantz father figure because his central to the formation of Henig. Weidenfeld & Nicolson: approach to data collection and almost any new science. Most London. 2000 ISBN 0 297 643 analysis was so thoroughly researchers, even in Bateson’s 657. Throughout, for Mendel, modern. Mendel was a day, spend most of their time in read Bayes. “Every new science twentieth-century scientist laboratories that look and feel needs a hero - someone on trapped in the nineteenth like factories. If they can keep in whose giant shoulders his century, and the romance of his mind some brilliant, founding disciples can stand - and story was that he died father, some scorned or Mendel was an easy man to unappreciated and embittered, unappreciated genius in whose lionise. Partly because so little mired in a dreadful silence that footsteps they now loyally was known about his actual engulfed him and his reputation tread, they can more easily biography, and because the little for thirty-five years. But none of maintain their sense of mission that was known was so this would have caused anyone through even the most routine, admirable - solitary, devout, to turn Mendel into the inconsequential chores.” So gentle, humourous, modest - the founding father of genetics if it now I know why it is called Moravian monk was an ideal were not for the much more Bayesian statistics. Incidentally, tabula rasa on which latter-day critical point: Mendel had been the book is highly to be Mendelians could etch a tale right. The mythologizing that recommended. that it pleased them to think turned Mendel from monk to

TWO NEW PRIZESIN applications, and including awarded biennially. The first STATISTICAL SCIENCE teaching texts at any level. DeGroot Prize will be awarded The Lindley Prize will be following the competition in A consortium of statistical awarded for innovative research 2001. The first Lindley Prize will organisations has established in Bayesian Statistics that is be awarded following the two new professional prizes: the accepted for publication as a competition based on DeGroot Prize and the Lindley contributed paper in the contributed papers in the Prize, honouring the eminent refereed proceedings of the proceedings of the 7th Valencia statisticians Morris H. DeGroot Valencia and ISBA international International Meeting on and Dennis Lindley. meetings. Award winning Bayesian Statistics, to be held in The DeGroot Prize will be papers will present research in Spain in 2002. awarded in recognition of a Bayesian statistics that is is The International Society for published book in statistical judged important, timely and Bayesian Analysis (ISBA), one science. Candidates for the notably original; truly of the founder organisations, DeGroot Prize will be judged on innovative work will be judged has assumed responsibility for the extent to which the book more highly than successful the management and represents an important, timely, development of ideas administration of the two thorough and notably original previously exposed. The awards. contribution to the statistics Lindley Prize may be awarded Full details of the two prizes, literature, whether textbook or for work in foundations, theory, including the governing monograph. The DeGroot Prize methodology and applications charters and the list of founding may be awarded for a book of Bayesian statistics. organisations, can be found at addressing fundamental issues Each of the prizes consists of the ISBA website of statistical inference, decision an award of $1500 and a www.bayesian.org/awards/ theory and/or statistical commemorative plaque and is awards.html

5 ISBA Bulletin, December 2000 BAYESIAN HISTORY

ISBAHISTORY State U.), Jacques Dreze (U. of Research Foundation for their AND MEETINGS Louvain), Yoel Haitovsky (U. of financial support.” (p.2) In a Jerusalem), John Hsu (UC Santa December 1992 letter to the by Arnold Zellner Barbara), Dale Poirier (U. of ISBA Board Members, Arnold [email protected] Toronto), Herman van Dijk Zellner wrote: “I am writing to (Erasmus U. Rotterdam), invite all Board members to The opening paragraph of the Enrique de Alba (ITAM, Mexico serve on the Program first issue of The ISBA City), Luis Pericchi (Univ. Committee for the 1993 ISBA Newsletter, Nov. 1992, edited by Simon Bolivar, Caracas) and J.K. meeting in San Francisco... Thomas Leonard, reads: Ghosh (Indian Statistical Robert McCulloch has agreed to “Following worldwide Institute), International serve as Program Chair and enthusiasm, positive votes at Advisors; Seymour Geisser (U. John Geweke as a member of Bayesian Conferences in Rio de of Minnesota), Chairman of the the Program Committee...As Janeiro, St. Paul, Valencia and Council of Sciences. A regards invited paper sessions, Cambridge, and letters of permanent board will be elected a group of us, including Shanti support from Brazil, the United by postal ballot prior to the first Gupta, met with Seymour Kingdom, Spain, Japan, China, annual meeting.” On Nov. 10, Geisser, Chair of the ISBA Taiwan, Hong Kong, 1992, ISBA was incorporated as Council of Sciences at the recent Switzerland, Poland, New a not for profit corporation in wonderful Workshop of the Zealand, the United States, [and the state of Illinois by Gordon Americas on Bayesian Statistics many other countries], the Kaufman, Tom Leonard and and Econometrics in Caracas, acting board announces the Arnold Zellner. See Venezuela to plan about eight formation of ISBA. This world www.bayesian.org, ISBA invited paper sessions dealing organization seeks to benefit Archives, Service to the ISBA, with Bayesian analysis in international society by the for more information on those various sciences and areas of advancement of Bayesian who have served ISBA over the application...Also, a cocktail statistics, science and analysis in years. party on Friday and a dinner on the natural, biological and social The First World Meeting of Saturday are being arranged...J. sciences, engineering, industry, ISBA was held in San Francisco, Stuart Hunter, then President of medicine, law, government and August 6-7, 1993 jointly with the ASA wrote that he would education, and by the NBER-NSF Seminar on address the dinner in the development and interface of Bayesian Inference in following words: “You asked inferential and decision making Econometrics and Statistics just for a “title for my presentation”. procedures in all areas...The before the annual Joint I do not plan to do more than current acting members of the Statistical Meetings. The Oct. confess my Bayesianism and to temporary board are Arnold 1993 ISBA Newsletter, edited by say a few words of greetings as Zellner (U. of Chicago) and Jose Jeff Dorfman, U. of Georgia, and the president of the ASA.” Bernardo (Generalidad Valencia Tom Leonard, U. of Wisconsin There was a Board meeting at Presidencia), Co-presidents; commented as follows on the which a Nominating Committee Michel Mouchart (U. Catholique meeting: “Our first world (J. Bernardo, D. Fong, S. Geisser, de Louvain), Secretary; Gordon meeting was a great success, M. Mouchart, Chair and Kaufman (MIT), Treasurer; with nearly 200 participants S.J.Press) was appointed to Thomas Leonard (U. of packing into the Hotel Nikko in organize the first ISBA election Wisconsin), Newsletter Editor San Francisco. Congratulations of a President, Vice-President, and Constitutional Advisor; to organizer Rob McCulloch, on Treasurer, Secretary and 12 James Press (UC Riverside), a wonderful meeting. Thanks to International Advisors. Also, Intersocietal Representative; Chase-Manhattan Bank [Jose other weighty matters were Dennis Lindley (Somerset, Quintana], Electric Power discussed. At the Open Business England), Hajime Wago (U. of Research Institute [Stephen Meeting reports were made and Toyama), Duncan Fong (Penn Peck] and H.G.B. Alexander all were encouraged to follow

6 ISBA Bulletin, December 2000 BAYESIAN HISTORY the 11th Commandment, “Make financial, membership, and of “hostesses”, those beautiful the pie bigger for all!” local arrangements reports by girls dressed in typical local Many of the papers presented Gordon Kaufman, Susie Bayarri costumes who accompanied the at the meeting were included in and Michel Mouchart, the Board participants during registration a 1993 proceedings volume heard a report of the results of and providing coffee and drinks produced jointly with the ASA the first ISBA election of a Board between the sessions. The Section on Bayesian Statistical and International Advisors. Jay Rector of ITAM (Mexico City), Science. The invited paper Kadane, ISBA’s Thomas Dr. Arturo Fernandez, was also sessions included talks on Jefferson, was given the very supportive of the event, Bayesian analysis on Wall Street, responsibility for preparing a both financially as well as with in engineering, psychology, draft of an ISBA constitution. It personnel and physical environmental science, physics, was unanimously agreed that resources...After the dinner a astronomy, geology, the next world meeting of ISBA Folkloric local group presented econometrics, and Bayesian would be held in 1995 in typical dances from each of the education. Contributed paper Oaxaca, Mexico followed by a seven regions of the State of and poster sessions dealt with a 1996 meeting in South Africa to Oaxaca. The event was wide range of theoretical and help celebrate the peaceful extremely colorful and provided applied topics. Wes Johnson, U. transition from apartheid to foreign guests a taste of Oaxaca. of California at Davis, Chair of freedom. Friends from South At the closing banquet on the Local Arrangements Africa sponsored a lively Saturday night, awards were Committee and the committee cocktail party for the presented to Edward George members, Richard Barlow, participants, a brief introduction and Enrique de Alba in Garth Hollaway, William Jewell to the warm hospitality that we recognition of their fine work in and Dale Poirier did a great job were to experience in our 1996 arranging the meeting. Also, in all respects. The parties, meeting in Cape Town. Edward George joined John dinners, etc. were outstanding. As reported in the ISBA Deely to make the famous Deely Last, but not least, Pam Eckert, Newsletter, Dec. 1995, “The Awards to some who my secretary, played a key role Third World Meeting of ISBA participated in the meeting [A in making the ’93 and later ISBA held in Oaxaca, Mexico, was Deely rose was given to my wife meetings very successful. very successful with about 174 Agnes for putting up with me The Second World Meeting of in attendance. There were three for so many years!]. Thanks ISBA was held in Alicante, parallel sessions on Friday and were also expressed to the Spain, June 10-11, 1994, just Saturday, September 29-30 as Governor and Rector for after a Valencia Meeting with well as an extensive Friday funding the banquet and their 151 official participants in evening poster session and two other contributions, and to Dr. attendance. The meeting was banquets. Edward George and Jose Quintana and Dr. Stephen held in the Hotel Melia, located his Program Committee C. Peck for obtaining funds to between the beach and the arranged the full and help meet participants’ travel yacht harbor. Michel Mouchart, worthwhile program. They did and other expenses.” Many of U. of Louvain, was Program an excellent job of selecting and the papers presented at the Chair and M. J. (Susie) Bayarri, grouping the talks. Enrique de meeting were published in the U. of Valencia was in charge of Alba, President of the third joint ISBA/SBSS local arrangements. Also, S. Organizing Committee and his Proceedings Volume. Enrique James Press, U. of California at colleagues made arrangements de Alba wrote in the ISBA Riverside announced the first for the meeting that were Newsletter that, “Of the Mitchell Award of $1,000 for a excellent...The Governor of the participants 52 were students, “paper describing how a State of Oaxaca, Mr. Diodoro 48 Mexican and 4 Bayesian analysis has solved a Carrasco generously provided American...Thus overall, the truly applied problem.” At the the opening dinner as well as meeting was a big success in ISBA Board meeting, after logistic support and the group terms of attracting students

7 ISBA Bulletin, December 2000 BAYESIAN HISTORY so that they can be introduced presented papers made the workshop papers and notes, to the Bayesian approach to meeting a “Wonderful Moment and a 140 page provisional text Statistics.” of Bayesianism”. Dan De Waal in Contemporary Bayesian The new Chair of the Council was Program Chair for the Econometrics by John Geweke. of Sciences (COS), Don Berry of meeting and many outstanding Software was also made Duke U. met with a group to statisticians, including Abrie available by Arnold Zellner. plan future activities of the van der Merwe, Paul Fatti and Software offered by John COS. In 1995, Jeffrey Dorfman Piet Groenewald from South Geweke required higher levels announced the appointment of Africa participated. Besides of hardware than are currently an Editorial Board for The ISBA tours organized by the available in Africa, but as Newsletter. The Associate outstanding conference hardware improves there would Editors appointed were: Robert organizer Tim Dunne (U. of be access to his package. The Kohn, U. of New South Wales, Cape Town), many of us took workshop events involved Jack Lee, National Chiao Tung the opportunity for a longer introductory presentations and U., Udi Makov, U. of Haifa, stay in South Africa. Many from educational views, but some Ludovico Piccinato, U. of Rome, South Africa made research issues were also Mark Schervish, Carnegie presentations and/or chaired discussed. There were 20 Mellon U., Hiroki Tsurumi, sessions at this ISBA meeting participants (other than the Rutgers U., and Alyson Wilson, and impressed participants with leading speakers) of whom 10 Duke U. Further, in 1995, Carlos their deep knowledge of were from South Africa, 4 from Rodriguez, State U. of New modern Bayesian principles and Zimbabwe, 3 from Uganda, 2 York in Albany and Richard techniques. The 28-page report from Botswana and 1 from Silver, Los Alamos National of the meeting contains a listing Ethiopia. Participants from all Laboratory established a Web of sessions, papers and abstracts the African countries recorded site for ISBA and a Bayesian of presented papers. their delight at the initiative Analysis E-Print Archive. These As mentioned above, an taken by ISBA. They were developments were a Education and Research particularly grateful for the forerunner to the work of Mike Workshop in Bayesian Analysis printed material and program Evans, U. of Toronto in creating (ERWBA) was held just before diskettes...Specific thanks were the wonderful, current ISBA the ISBA meeting. In a report, extended by participants to all website, www.bayesian.org. Go Tim Dunne describes this persons involved in the to it and enjoy learning about workshop meeting, financed by generation of the NSF part current and past developments. grants from the U. of Cape sponsorship of the The Fourth World Meeting of Town and the U.S. National workshop...This enthusiasm ISBA with over 100 in Science Foundation, as follows: resulted in the formation of an attendance was held in Cape “The programme was devised African chapter of ISBA a few Town, South Africa, Dec. 17-20, by Arnold Zellner...He invited days later during the 4th World 1996, preceded by an Education Professors S. James Press meeting of ISBA. All the and Research Workshop in (Riverside), Stephen Fienberg participants stayed over to be at Bayesian Analysis, Dec. 14-16. (Carnegie-Mellon), John that event. Participants were of As reported in the May 1997 Geweke (Minnesota), Alicia the view that many persons in ISBA Newsletter, produced by Carriquiry (Iowa State), Theo areas of the globe similarly the new editor, Frank R. Stewart (Cape Town), and disadvantaged by national Kleibergen, Erasmus U., Balisyar Bhat (Botswana), and poverty and constrained higher Rotterdam, “Escaping winterly PhD candidate Andrew Ainslie education infrastructures might climates all around the world (Chicago) to lead various benefit from similar ERWBA many Bayesians visited the sessions of the workshop. events...Accordingly, the ISBA 1996 World Meeting in Two documents were participants recorded their Cape Town...The broad range of produced for participants: a 280 suggestions that ISBA and NSF topics and the quality of the page bound collection of the offer similar workshops in

8 ISBA Bulletin, December 2000 BAYESIAN HISTORY regions such as South America “Ninety three participants from 2000, “...Our Sixth World and the fringes of the Pacific 16 countries attended...The Meeting...was a tremendous rims of progress... [Prof. Dunne]. program consisted of 14 invited success. Ideally situated at Needless to say, foreign sessions, including two panels, glorious luxury hotels, an attendees at the meeting joined 3 contributed sessions and a impressive scientific program of South Africans at the Monday poster session. The 126 talks and 108 posters was Cocktail Evening and the presentations provided an presented. The Bayesian spirit Wednesday trip to Groot up-to-date overview of of hard work and hard play was Constantia in many toasts in theoretical and applied research ever present, and a productive honor of those who made in Bayesian statistics. and fun time was had by all. possible the peaceful transition Applications covered a wide The bulk of the planning and to freedom and democracy. range of disciplines, such as implementation of ISBA 2000 Given the intense “strains” of engineering, biological sciences, was carried out by three such meetings, etc., it was economics, law, medicine, and committees—the Program decided in Cape Town that ISBA social sciences.” As Mark Steel, Committee (Mike West, Chair), would hold World meetings ISBA Vice-Program Chair, the Finance Committee (Alicia every four years beginning in noted, papers presented in Carriquiry and Stephen 2000. (See Newsletter, May 1997 Istanbul and in Cape Town are Fienberg, Co-Chairs and the for details of the Program eligible for inclusion in the 1997 Local Organizing Committee Committee Report). Proceedings volume of the (George Kokolakis, Chair). The Fifth World Meeting of ASA’s Section on Bayesian These committees, especially ISBA was held in Istanbul, Statistical Science. Also, this the chairs, did a superb job, and Turkey, August 16-18, 1997 as a very successful and productive their tireless efforts are most satellite meeting of the 51st meeting included a Gala Dinner gratefully acknowledged. A Session of the International and Cruise on the Bosphorus refereed proceedings volume is Statistical Institute (ISI) in from 6:00-12 midnight on in the works, and will be Istanbul and took place in the Sunday, Aug. 17 following a published and distributed by Istanbul Polat Renaissance Saturday dinner at Le Chateau Eurostat, who co-sponsored the Hotel. A very fine program was Restaurant. And, of course, meeting. In addition to all this produced by Hamparsum there was the famous or generous support, Eurostat will Bozdogan (U. of Tennessee) and infamous Deely Award also distribute a complimentary Refik Soyer (George ceremony with John Deely copy to all current ISBA members.” Washington U.), Co-Program presiding, assisted and abetted As regards fun, those Chairs and their committee. by Steve Fienberg, 1997 attending were treated to one of Ulku Gurler (Bilkent U., Turkey) President of ISBA. Also, David the most unusual after dinner and his Organizing Committee R. Cox (Oxford U.), President of performances ever presented in made local arrangements that ISI, shared his thoughts on the history of the human race. were exceptionally fine. The 45 Bayesian analysis with us at a Strange human beings, said to page Scientific Program for the session involving deep and be a wild clan of Bayesians, clad meeting contained much useful insightful presentations by Jim in most outlandish garb danced information including Berger, Jayanta Ghosh, and Jose and sang to amuse an attentive acknowledgements of financial Bernardo. Overall, the meeting audience under a clear night and technical support from the was a memorable event that we sky. It was awesome. Another Turkish Scientific & Technical shall long remember. night, it was Greek food for Research Council, U. of The Sixth World Meeting of dinner followed by village Tennessee, George Washington ISBA, ISBA2000 was held in dances with the audience going U., U.S. NSF, and OTARI Hersonissos-Heraklion, Crete, native and participating in the TOURS, Istanbul (where East May 28-June 1, 2000. As Ed wonderful Greek frolics until all meets West). According to the George, ISBA Program Chair hours of the night. Oh yes, we ISBA Newsletter of Sept. 1997, wrote in the ISBA Bulletin, June did work hard, as Ed George

9 ISBA Bulletin, December 2000 BAYESIAN HISTORY / TEACHING mentioned above. Indeed many with help from many others, Processes, Madrid, Spain. of the sessions were jointly organized the Taiwan meeting Further, the ISBA Chapters in sponsored with Eurostat, an and Robin Carter, U. of W. India, South Africa, and Chile interaction that will Ontario, then visiting the U. of have sponsored very effective undoubtedly result in many Chicago, was a key person in workshop meetings. Bayesian improvements in organizing the Chicago 1996 With all this past and current the production and use of official meeting. ISBA has also activity, we conclude that a government statistics worldwide. co-sponsored four meetings, Bayesian Era has arrived! For In addition to the above namely, The 1995 Second further evidence, see Jim World Meetings, there have International Workshop on Berger’s December 2000 JASA been three lively regional Bayesian Robustness, Rimini, article, especially Section 2, meetings in Toronto, Canada, Italy, The 1997 17th Maximum Bayesian Activity. 1994, Taipei, Taiwan, 1994 and Entropy and Bayesian Methods Congratulations to all ISBA Chicago, U.S., 1996. Mike Evans Workshop, Boise, Idaho, U.S.A, members for the important role and his colleagues at the U. of the 1998 Sixth Valencia that they have played in Toronto played a key role in International Meeting on creating the Bayesian Era. arranging the outstanding Bayesian Statistics, and the 1998 P.S. ISBA was (re)incorporated Toronto meeting. Jack Lee, Wes Workshop on Bayesian in the State of Iowa, by Alicia Johnson and Arnold Zellner, Inference and Stochastic Carriquiry, on March 16, 2000.

ACASE STUDY THAT MAKES Students learn the differences (1996) and a supplement to the THE CASEFOR TEACHING between observational studies Freedman et al. text written by BAYESIAN METHODSTO and controlled experiments, Michael Lavine and myself. The UNDERGRADUATES how to describe the distribution students see binomial and of a single variable and the normal data examples. In the by Dalene Stangl relationship between two binomial-data examples we use [email protected] variables using graphical and both discrete and continuous numerical techniques, and how parameter spaces. Conjugate For the last 5 years, I have to use the basics of probability. beta priors are used for the been advocating teaching The probability section of the latter. Then we look at Bayesian methods in book is supplemented with my normal-data examples with a undergraduate service courses, own segments on conditional continuous parameter space for i.e. courses designed for probability and Bayes theorem. the mean. Again we use a non-statistics majors. At Duke, The second half of the conjugate prior. Students learn we’ve learned that you can’t semester does not look like to calculate the posterior and teach primarily the Bayesian other introductory statistics predictive distributions. paradigm without upsetting classes. First, we cover Throughout, the emphasis is other departments. What you frequentist inference, seeing on thinking through Bayes can do is present both confidence intervals, theorem, updating beliefs, and frequentist and Bayesian (Observed-Expected)/Standard making predictions about future paradigms with equal emphasis, Error, and hypothesis testing in observations. and encourage students to a half-dozen different contexts. Time allows 4 formal lectures ponder the differences. My Then we start over with on Bayesian inference followed strategy follows. Bayesian inference. We define by 2 lecture periods that cover a The first half of the course subjective probability and case study. The case involves looks like many other review Bayes theorem. This the GUSTO clinical trial, a trial introductory statistics classes. segment borrows heavily from comparing tissue plasminogen We use Statistics by Freedman, Statistics : activator (t-PA) and streptokinase Pisani, and Purves (1998). ABayesianP erspective by Berry (SK) for the treatment

10 ISBA Bulletin, December 2000 TEACHING of myocardial infarction. individuals: 1) a government paradigm. Students learn to The results of the trial were policy maker deciding whether make persuasive statistical first presented in the New Medicare will pay for t-PA, the arguments and are better able to England Journal of Medicine more expensive treatment, 2) an critique others’ statistical (1993) and were subsequently insurance company executive arguments. Students learn that reanalyzed by Brophy and deciding whether their there are alternative ways of Joseph in the Journal of the company will pay for the more thinking and publishing, and it American Medical Association expensive drug, and 3) a is their choice. Students learn (1995). The statistical argument son/daughter whose parent that statistics are a tool for in the NEJM paper uses was given the more expensive decision making. Students learn confidence intervals and tests of drug, and the insurance that statistics will be useful for significance. Finding an company is refusing to pay. most everything they do and increased survival of 1% and They must present a written read for the rest of their lives. rejecting the null hypothesis of statistical argument (Bayesian ➤ References no difference between or Frequentist) to defend each treatments, the GUSTO position. ALBERT,J. (1997). Teaching Bayes’ investigators conclude that t-PA In the second role-playing rule: A data-oriented approach. The American Statistician, 51(3): 247-253. is clinically superior. In the exercise, a mock legal trial, JAMA paper, Brophy and students are given roles of BERRY,D.A. (1997). Teaching Joseph use Bayesian statistical plaintiff, defendant, prosecuting elementary Bayesian statistics with arguments to argue that the jury attorney, defense attorney, or real applications in science. The American Statistician, 51(3):241-246. is still out. They find that the expert statistics witness (one for posterior probability that each side). The case they must BERRY,D.A. (1996). Statistics: A survival on t-PA is greater than enact is a malpractice suit Bayesian Perspective. Duxbury Press. survival on SK by at least 1% against a doctor who prescribes BROPHY,J.M. and JOSEPH,L. ranges from 0% to 36% the SK, cheaper drug, and the (1995). Placing trials in context depending on how much patient dies. using Bayesian analysis: Gusto weight is placed on previous Both the written exercise and revisited by Reverend Bayes. trials. A third source for the case the mock trial have worked Journal of the American Medical is an article, “The Mathematics well. The trial works best when Association, 273(11): 871-875. of Making up Your Mind”, by you have pre-law and pre-med FREEDMAN,D.,PISANI,R. and W. Hively. The article appeared students in the class. It can be PURVES,R. (1997). Statistics, 3rd in the popular science magazine hilarious when you have Edition, Norton. Discover in May, 1996. It covers students with acting experience. HIVELY, W. (1996). The the differences between Regardless, it is wonderful to mathematics of making up your inferential paradigms and see the wheels churn as mind. Discover, May: 90-97. highlights the controversies that students sift through the STANGL,D. (1998). Classical and can arise between them. The inference issues while Bayesian Paradigms: Can We Teach article uses the GUSTO trial as presenting their arguments. Both. In Proceedings of the Fifth their primary example. What does this case study International Conference on Teaching After introducing and teach the students? Students Statistics, (L. Pereira-Mendoza, L.S. discussing the case, there are love what George Cobb calls Kea, T.W. Kee and W. Wong Eds.), two student exercises both “authentic play”. That is, they International Statistics Institute, 1, 251-258. based on role-playing. One is a love to imitate what they will written exercise, the other a actually be doing as THE GUSTOINVESTIGATORS mock legal trial. Students are professionals. This case is an (1993). An international expected to use the information excellent example of authentic randomized trial comparing four from the three articles. In the play. At the same time it brings thrombolytic strategies for acute written role-playing exercise to light the advantages and myocardial infarction. New England students are asked to role-play 3 disadvantages of each Journal of Medicine, 329:673-682.

11 ISBA Bulletin, December 2000 BRAZIL

BAYESIANS wrote up a Bayesian MA Rodrigues, Heleno Bolfarine IN BRAZIL dissertation. A few years later, and Jorge Achcar established a Carlos went to Florida to get his firm research activity and by Sergio Wechsler and PhD from Debabrata Basu. influenced many young people Basilio de Braganca Pereira Upon his return to USP in the to follow Bayesian careers. Jose [email protected] late Seventies, Bayesian Galvao Leite wrote his PhD [email protected] activities in Brazilian academia dissertation on Bayesian “ Let us suppose that an finally unfolded in a strong and capture-recapture sampling individual, I , is provided with a regular fashion. The multiple - under Carlos Pereira certain set, C , of knowledge but always Bayesian - interests supervision. His MA students and that I ought to behave of Carlos Pereira influenced Telba Irony and Angela dependently on the occurrence many researchers at Sao Paulo. Mariotto went to get their or not of a given event, E .” Among his early PhD students doctoral degrees from Dick “ ... the subjective notion of we find the geneticist Andre Barlow on Bayesian industrial probability aims exactly to Rogatko. Josemar Rodrigues engineering and Sir Cox, measure this degree ... of was at USP faculty and wrote respectively. In Rio de Janeiro, belief... ” several papers jointly with Helio Migon and Dani These are excerpts (translated Carlos Pereira on linear models Gamerman had returned from from Portuguese) from the and finite populations. Another Warwick, having obtained their “Introduction to Probability faculty member, Heleno PhD degrees under the Calculus” class notes used Bolfarine, returned from supervision of Jeff Harrison and during the Fifties at ENCE Berkeley in 1982 to start a Mike West, respectively. Helio (Escola Nacional de Ciencias brilliant career on Bayesian and Dani have been supervising Estatisticas - National School of theoretical statistics. Bayesian dissertations since Statistical Sciences) in Rio de At that time in Rio Basilio 1987 at COPPE/UFRJ (Graduate Janeiro. The notes were written Pereira, a student of Sir David School of Engineering/UFRJ) by Professor Rio Nogueira and Cox, started to supervise some and from now on at their home constitute the earliest reference Bayesian students and hosted a department, DME (Statistical to subjective probability we first visit of Adrian Smith of Methods Department), which have found in Brazilian three months in 1980. Basilio has just started to offer a regular writings. In fact, it is a nice (Carlos’ brother) proceeded and PhD program in Bayesian surprise to find a Brazilian created the Bayesian Statistics. relative I of de Finetti’s atmosphere at UFRJ (Federal During the Nineties, Bayesian character You ! [ENCE still University of Rio de Janeiro) activities in Brazil started to exists and is an undergraduate where Marlos Viana, Helio make good impact in other school of Statistics maintained Migon and Dani Gamerman countries as foreign students by IBGE , the Brazilian Census would later appear to make the returned to them. From USP Institute. A few of the people department an excellence center Daniel Paulino returned to mentioned below graduated on Bayesian research with Portugal after getting a PhD from ENCE]. sound contributions in from Carlos Pereira. Victor Let us now move to the econometrics, dynamical Salinas Torres and Pilar Iglesias, Sixties at Berkeley, where Caio models, time series, both from Chile and both Dantas, a probabilist from Sao epidemiology, survival analysis, Pereira’s PhD students returned. Paulo, attended the seminars stochastic simulation. Back in Chile, Pilar Iglesias has held by David Blackwell and We are by now in the Eighties been provoking good Bayesian Lester Dubins. Dantas brought and our story becomes way less earthquakes since then. Luis back a Bayesian seed (and also linear as the branches of the Eduardo Montoya Delgado is Blackwell’s Basic Statistics book) Brazilian Bayesian tree start to back in Colombia after a superb to USP (Universidade de Sao become many. At Sao Paulo, PhD on DNA profiling for Paulo) where Carlos Pereira Carlos Pereira, Josemar paternity investigation.

12 ISBA Bulletin, December 2000 BRAZIL

Veronica Gonzalez-Lopez in but we prefer to hurry them up probabilists who would not Argentina is the most recent (not to mention that we intend consider themselves exclusively member of this impressive list of to write the Second part of this “Bayesians”: we find Carlos’ PhD students. Paulino story ten years from now). outstanding contributions from worked on identifiability, Torres Before getting too close to Pablo Ferrari on Image on Bayesian non-parametrics year 2000, we should remember Restoration, Antonio Galves on and Dirichlet process, Pilar on the series of bi-annual Bayesian Linguistics, both at USP, Renato predictivistic representations, Brazilian Seminars held since Assuncao at UFMG (Federal and Lopez on Bayesian concepts 1991. The first one was at Sao University at Minas Gerais) on of dependence. At the same Carlos and chaired by Josemar Spatial Statistics and Disease department, Heleno Bolfarine Rodrigues and Sergio Wechsler. Control, Pedro Morettin (USP) supervised students like In 1993, the Seminar was held on Time Series. The work by Reynaldo Arellano Valle whose jointly with the International Fabio Cozman, a Carnegie PhD dissertation won a first Bayesian Hierarchical Meeting Mellon Ph.D in Robotics prize award at the Bernoulli of Rio de Janeiro organized by recipient, is illustrated in the Society Clapem contest. Valle is Dani Gamerman and Helio software section of this issue. back in Chile and worked on Migon and attended by We should also list the external predictivistic Bayesians like Jose Bernardo, bibliographical contributions of representations of elliptical Adrian Smith and Phil Dawid Brazilian Bayesian authors: to families. Loretta Gasco at Peru (who would return for the third mention books only, Heleno and Patricia Gimenez at Mar del Brazilian Bayesian two years Bolfarine is co-author of S. Plata were also Bolfarine’s later). Before that , in 1992, we Zacks’ book on Finite doctoral students. Heleno had in Rio a joint Brazil-US Population Estimation, Dani Bolfarine and Pilar Iglesias were Meeting on Bayesian Gamerman wrote Monte Carlo PhD advisers to Marcia Branco Econometrics chaired by Ruben Markov Chain: Stochastic and Rosangela Loschi. All this Klein and attended by Arnold Simulation for Bayesian Inference people have very strong and Zellner and Jay Kadane among and, jointly with Helio Migon, active scientific collaboration. many others. [Omissions are Statistical Inference: an Integrated We have recent papers by unavoidable at this point and Approach . Going back to the Gonzalez-Lopez and Nelson we apologize for this. Jim beginning, we find translations Tanaka, Bolfarine and Valle and Berger, Susie Bayarri, Ed to Portuguese of Blackwell’s so on, not to mention Pilar George, Dale Poirier, Seymour Basic Statistics and Raiffa’s Iglesias whose admirable drive Geisser, Alicia Carriquiry, Tony Decision Analysis already in the puts almost everyone to work. O’Hagan, Steven Fienberg, Jim early Seventies. Carlos Pereira The brand new generation of Press, Alan Gelfand and Luis and Marlos Viana wrote a book Brazilian Bayesians includes Pericchi among again many in 1982 on Introductory Bayesian Lurdes Inoue who after a PhD others were also in Brazil a Statistics which was never from Donald Berry at Duke is couple of times. The department translated from Portuguese. now at the MD Anderson at USP was visited by Dev Basu, Bayesian research activities Cancer Center at Houston and Dennis Lindley, Dick Barlow are now very active in Brazilian Hedibert Lopes who also amd S. Zacks. Adrian Smith and universities with strong graduated from Duke and is Tony O’Hagan visited UFRJ interaction with universities now at UFRJ faculty. Both got more than once]. During the abroad. Last year the Brazilian MA degrees in Brazil formerly, 1992 Meeting a vote was taken Bayesians decided to create a Lurdes from Sergio Wechsler for the creation of ISBA. Brazilian Chapter of ISBA. The and Hedibert from Helio Migon. Also during the Nineties a new Chapter made the decision A list of several almost-PhD diffusion of Bayesian ideas and to host the First “Latin American Brazilian Bayesian students at methods occurred among Bayesian Meeting” ( I COBAL) USP, UFRJ, Duke, Sheffield, researchers from other areas to be held very probably on Cambridge .... could be given and statisticians and January 2002 in Brazil.

13 ISBA Bulletin, December 2000 APPLICATIONS

BAYESIAN INFERENCE particular locations along the at the first 9 locations. It was last FOR FOSSIL RECORD stratigraphic section and the observed at location 5.4 meters, DATA number of specimens yij found and was never observed again; is recorded for each taxon j. the first two non-occurrences by Sanjib Basu, Locations ti are measured in were at 5.9 and 6.1 meters. Since Robert E. Weiss meters of rock above an this species was always and Charles R. Marshall arbitrary baseline. The distance observed until it disappeared, [email protected] between samples may be we might suspect that the [email protected] uniform, or may be based on species became locally extinct [email protected] where samples can be readily between 5.4 and 5.9 meters. In collected. The total number of contrast, species 27, Bathysiphon We describe a fundamental specimens identified at each sp., was present in 5 locations framework for Bayesian location is ni. In many data sets, and absent at 12 locations inside inference from fossil record presence, y = 1, and absence its observed range. It was last data. ij yij = 0 out of a nominal ni = 1 is observed at height 9.2, then absent at 9.9, 10.2 meters and on Fossil data are commonly all that is recorded. through the top of the section. collected by Paleontologists to Maximum likelihood Because omissions are more answer questions about the estimates of the true end-points common than not for species 27, history of life and may be used of a taxon’s stratigraphic range we anticipate that the first few to estimate a taxon’s (i.e. are the observed beginning and absences above the last presence species) time of origin and its end points in the data set. This are more likely omissions from time of extinction. Values of is equivalent to a literal reading the fossil record rather than these parameters are important of the fossil record. In the evidence of its extinction just for testing hypotheses about absence of better methods, above its last presence. origination and extinction, for paleontologists may use the evaluating phylogenetic observed range as an estimate Our goal is to make these hypotheses and for calculating of the true range and ignore qualitative arguments more pre- species turnover rates, among uncertainty in the end point cise through use of a statistical others. However, the fossil estimation. model. We begin with a setup al- The goal of our research has record is typically incomplete. ready described (Weiss and Mar- been to develop Bayesian There are generally gaps within shall, 1999) (WM), where origi- inference for fossil record data. the observed stratigraphic range nation occurred before t1 = 0.0. Weiss and Marshall (1999) and more importantly, there Thus we need only model the analyzed data taken from 36 may also be gaps between the extinction time. The data yij unevenly spaced samples of 100 endpoint of the observed range are the observed presence or grams of rock collected from and the true end points. These absence of species j at height three cliff faces of gaps may result either from i and where yij = 0 may sim- Cenomanian-Turonian outcrop, failure of nature’s preservation ply be due to a false absence or deposited some 95-90 million processes or failure of omission rather than due to ex- years ago in Eastbourne, Sussex, paleontologist’s collection tinction. WM modeled the yij’s U.K (Vaziri, 1997). The 36 practices. The true end points as Bernoulli(πij ), separately for samples were taken at heights are the end points that would each species where πij denotes of 0, 1.4, 1.6, 2.3,3.9, ... 31.4 have been observed if the fossil the probability of observing the meters from bottom. Sixty seven record and human data species in a sample prior to ex- species were identified; all are collection provided a flawless tinction. The parameter of inter- assumed to have been present at record of species presence. est is Ej, the extinction time of the bottom t = 0.0. We mention species j. WM assumes that the There are several ways of 1 two species as illustration; probability π = π is a constant sampling a stratigraphic section. ij j species 20, Gavelinella before extinction (t ≤ E ) and We assume discrete sampling, j j cenomanica was present (y = 1) where samples are taken at ij

14 ISBA Bulletin, December 2000 APPLICATIONS

πij is of course = 0 after posterior mean and median genus, paleontologists are extinction (tj > Ej). The extinction time are many interested in knowing whether resulting likelihood for species j hundreds of meters past the last different species originated or is non-standard. It depends on observed presence. The became extinct at the same time, the total number presences and posterior variance of E27 is large whether one species became absences between 0 and the time reflecting the uncertainty of the extinct at the same times at of extinction Ej. The likelihood results. If we change the prior different sites, and how the of extinction is a step function mean extinction time from 800 distribution among the species which is zero below/beneath meters to 40 meters or 2 meters, changes over time. the highest height tmax which the posterior mean for species In summary, fossil record has yij = 1. At tmax, the 27 changes by similar orders of analysis involves interesting likelihood jumps immediately magnitude. In contrast, the statistical modeling. Simple to a maximum. The likelihood is result for species 20 is maximum likelihood analysis is constant in between sampling insensitive to these changes to often equivalent to literal locations tj and drops at each the prior. reading of the fossil record. height tj > tmax. At the top of Our ongoing project is to Bayesian methods provide more the section there are no more develop a fundamental useful tools and are able to samples, and the likelihood then framework for Bayesian highlight hidden characteristics is perfectly flat and greater than analysis of fossil record data. of the data. In general, zero out to plus infinity. The These analyses will utilize paleontological interest focuses likelihood never drops to zero actual specimen counts for each on temporal and spatial relative for Ej > tmax. species out of total fossils diversity, and statistical models The prior for the extinction sampled at each location rather for these data and issues are time Ej was specified as than the presence-absence currently under development. exponential with a mean information described above. ➤ References longevity of 21 million years. We plan to include multiple This was converted to a mean of species in the analysis. The WEISS,R.E. and MARSHALL, 800 meters in the scale of counts of the different species at C.R. (1999). The Uncertainty in stratigraphic distance, utilizing a fixed height are modeled as a the True End Point of a Fossil’s prevailing knowledge of the multinomial. When species j is Stratigraphic Range When sediment deposition rate in the not extant, the multinomial cell Stratigraphic Sections are Eastbourne section. probability for species j is zero. Sampled Discretely. For prior specification of the This dynamically changes the Mathematical Geology, 31,435–453. probability πj, we borrow probabilities of observing the strength by using data from other extant species since these VAZIRI,M.R. (1997). Patterns other species. Data yik from probabilities add to 1. We wish of microfaunal occurrence species k with similar extinction to simultaneously estimate the across the times and similar fossil record birth and extinction times of all Cenomanian-Turonian recovery rates were pooled to species under analysis. boundary in England. create a Beta prior for πj. Motivation for this Unpublished doctoral dissertation, Our Bayesian analysis development is provided by University of Liverpool. estimates that species 20 became Upper Cambrian trilobite data THOMAS,R.C. (1993). The extinct within .5 meters after it collected at 13 different sites in Marjumid–Pterocephaliid was last observed in the fossil the western US (Thomas, 1993). (Upper Cambrian) Mass record. In contrast, species 27 The Thomas data has 34 Extinction Event in the Western was only intermittently different varieties of trilobite. In United States. Unpublished observed and the results are addition to estimating the time doctoral dissertation, University strikingly different. The of origin and extinction of each of Washington.

15 ISBA Bulletin, December 2000 SOFTWARE

THE JAVABAYES directed graphs that are acyclic system contains facilities for SYSTEM — graphs where it is impossible creating nodes, specifying to start at a node and reach the variables and probability by Fabio Gagliardi Cozman same node following directed values, saving and loading [email protected] edges. Given a node X in a networks. Networks can be ➤ Introduction directed acyclic graph, we can loaded either from files or from easily find the descendants of the the internet. The system is The goal of this brief paper is node (all nodes that can be coded in the Java language, to describe the JavaBayes reached from X). inheriting the portability aspects system, a software package that Suppose we have a of this language and benefiting manipulates graphical statistical multivariate statistical model from the language facilities for models known as Bayesian with N variables. We can operation with the internet and networks (also known as represent this model by a user interface construction. The Probabilistic networks, Belief directed acyclic graph with N fact that world-wide-web networks, Causal networks). nodes. We start by associating browsers support the Java The software package is freely each variable with a node. We language makes it possible to distributed at then define a conditional use JavaBayes directly in a web www.cs.cmu.edu/~javabayes distribution p(Xi|pa(Xi)) for browser. and has been adopted in several each variable Xi (the Once a Bayesian network is teaching and research distribution of Xi given the created or imported into the institutions as a vehicle for parents of Xi). The parents of a system, variables can be understanding, building and variable Xi are selected so that observed; that is, a variable can manipulating large statistical the following property is be fixed at a value. The models with categorical satisfied: Xi is independent of collection of all observed variables. The web site contains its nondescendants nonparents variables and their observed more information about given its parents. The result is a values is the evidence E in the JavaBayes, including a user graphical structure where each network (note that E may be manual in HTML and postscript node “contains” a variable Xi empty). Two types of statistical formats, downloadable files in and a distribution p(Xi|pa(Xi)). inferences can be performed by ZIP and TAR formats, and a The joint distribution is (Pearl, JavaBayes: description of the statistical 1988): inference algorithm • Computation of marginal probabilities for a variable X implemented in the system. YN q conditional on the evidence in ➤ p(X1,...,XN ) = p(Xi|pa(Xi)) . A quick tour on Bayesian the network. The objective is to networks and JavaBayes i=1 compute p(Xq|E). Such graphical models have A Bayesian network is a • Computation of a maximum been put to use in a variety of graphical representation for a a posteriori configuration of contexts (Jensen, 1996, and multivariate statistical model. variables X (where X can be a Whittaker, 1990), most notably q q The idea is to use directed acyclic set of variables). The objective is graphs as the basis for model in the BUGS system for generic to compute arg maxX p(Xq|E). construction. A directed graph Bayesian analysis q is a collection of nodes and (www.mrc-bsu.cam.ac.uk/bugs/). The inferences are performed by directed edges between nodes. Several examples that illustrate the variable elimination algorithm If an edge goes from node X to uses of Bayesian networks can (Dechter, 1999, and Zhang and node Y , then X is the parent of be found at the JavaBayes web Poole, 1996). This algorithm Y and Y is the child of X. The site. (also known as bucket parents of X are denoted by JavaBayes is a system for elimination) is quite similar to pa(X), and the children or X creating and manipulating the peeling algorithm used in are denoted by ch(X). Bayesian Bayesian networks containing genetics for pedigree analysis networks are constructed using categorical variables. The

16 ISBA Bulletin, December 2000 SOFTWARE

(Cannings and Thompson, By normalizing this function, contain a new, much improved 1981). The first step in any such we obtain p(Xq|E). JavaBayes inference engine. The new algorithm is to discard uses exactly this procedure to engine is substantially faster, distributions that are not compute posterior probability better designed and more needed in the computation — values, relying on heuristics to extensible, and it takes much such distributions can be generate an elimination order less memory to run than the detected by efficient algorithms, for variables (Jensen, 1996). current engine. All the code is thus saving considerable JavaBayes also contains a released with the executable, as computational effort (Geiger, generalization of the original the whole distribution is given Verma and Pearl, 1990). variable elimination algorithm under the Gnu-license. Note that we only need to in which intermediate results Consequently, everyone is compute p(Xq,E), because the are “cached” in a tree structure, welcome to contribute — you conditional p(Xq|E) can be so that a sequence of inferences are welcome to test and to try easily obtained by normalizing can be done with increased the system, and hopefully to p(Xq,E). We are then interested efficiency. The resulting scheme contribute to the evolution of in computing the following is similar to a junction tree JavaBayes. expression: algorithm (Jensen, 1996). The ➤ The future? extended algorithm is described p(Xq,E) = (1) in a paper that can be JavaBayes focuses on à ! downloaded from the JavaBayes categorical models, as these X Y web site (Cozman, 2000). models have received great p(Xi|pa(Xi)) , attention in artificial intelligence X ∈X ➤ The evolution of JavaBayes XR\{Xq ,E} i R research. There is great room for where XR indicates the set of The first version of JavaBayes improvement and extension. I variables that are effectively was coded in September 1996, see two areas in which needed in the computation shortly after the XII Conference JavaBayes can make a difference (after discarding unnecessary on Uncertainty in Artificial in an interesting way. distributions). Now, think of the Intelligence. JavaBayes was first First, teaching Bayesian various distributions in (??) as coded as a small library and analysis is still a difficult task. living in a “pool” of distributed in the internet with There are notable teaching tools, distributions. Suppose we a rudimentary user interface. perhaps the most interesting collect the distributions that The response to the first version being the FirstBayes system contain variable X1, take them was quite positive. Several developed by A. O’Hagan off of the pool, and construct the contributions were made by (www.shef.ac.uk/~st1ao/1b.html). (unnormalized but positive) users of the system; the most JavaBayes can be an interesting function notable was the user interface tool for teaching Bayesian   produced by Sreekanth analysis, because Bayesian X Y Nagarajan and Bruce networks are easy to visualize   p(Xj|pa(Xj)) . D’Ambrosio at University of and the system can be smoothly X1 X1,ch(X1) Oregon. Their graphical user used through the internet. But interface was integrated to the to be a complete teaching tool, Now we put this function into inference engine and formed the system must be enlarged, as the distribution pool. What we JavaBayes version 0.2. teaching requires the ability to have done is equivalent to Eventually, the whole inference display histograms, charts and “summing out” X ; that is, we 1 engine and the graphical user other statistical niceties, and the have eliminated variable X 1 interface were rewritten from ability to handle continuous from the problem. Following scratch, to become version 0.3. variables. the same procedure, we can The basic functionality of A second contribution of eliminate X , X , and so on. 2 3 JavaBayes has not changed JavaBayes is taking Bayesian Eventually we obtain an since then. analysis to the realm of unnormalized function of X . q The coming version 0.4 will

17 ISBA Bulletin, December 2000 SOFTWARE / STUDENT’S CORNER embedded systems — devices ➤ References networks. Networks, 20, 507–534. that work inside machines, CANNINGS,C. and THOMPSON, JENSEN, F.V. (1996). An utilities or vehicles. The E.A. (1981). Genealogical and Introduction to Bayesian Networks. economic value of embedded Genetic Structure. Cambridge Springer Verlag, New York. system has been growing University Press, Cambridge. exponentially; predictions PEARL,J. (1988). Probabilistic indicate that these systems will COZMAN, F.G. (2000). Reasoning in Intelligent Systems: soon be an important part of our Generalizing variable Networks of Plausible Inference. everyday lives. We can imagine elimination in Bayesian Morgan Kaufmann, San Mateo, air conditioning devices that do networks. In Workshop on California. Probabilistic Reasoning in weather forecast, or cars that WHITTAKER,J. (1990). Graphical predict traffic conditions. Artificial Intelligence (L.N. models in applied multivariate JavaBayes is well-positioned to de Barros, R. Marcondes, F.G. statistics. Wiley, New York. satisfy those needs, as it has Cozman, and A.H.R. Costa, ZHANG,N.L. and POOLE,D. been coded in Java (a language eds.), 27-32. Editora Tec Art, Sao˜ (1996). Exploiting causal with some special features for Paulo. independence in Bayesian embedded systems) and as it DECHTER,R. (1999). Bucket network inference. Journal of has been coded from the start to elimination: A unifying Artificial Intelligence Research, be lean and understandable. framework for probabilistic 301–328. To conclude, JavaBayes can be inference. In Learning in used now, and there are plans to Graphical Models (M.I. Jordan Note: Parts of this paper have keep improving it so as to ed.), 75–104. MIT Press, been based on an invited paper sent support the needs of the Dordrecht, The Netherlands. to the Workshop on Software Bayesian community and to GEIGER,D.,VERMA, T. and Support for Bayesian Analysis expand the reach of Bayesian PEARL,J. (1990). Identifying Systems, Colorado, 2000. analysis. independence in Bayesian

A FINAL COMMENT believe that a lot of work has to Dr. Dave Higdon be done to transform the Assistant Professor, by Maria De Iorio Student’s corner into a place to ISDS, Duke University, NC, [email protected] exchange ideas and hold U.S.A. constructive discussions about [email protected] research and our problems of Thoughts on Statistical Consulting In the past year I have common interests and to published articles about the job involve more and more I remember taking a course on market, and many recent students. I hope that the new statistical consulting as a Ph.D.’s have contributed with associate editors will continue graduate student. I also their personal experiences and in this direction and that it is remember sitting in consulting advice. In this last issue we going to be for them a fruitful sessions with a client, and a present an article by Dr. D. and challenging experience as it very knowledgeable faculty Higdon on “Statistical has been for me. Finally I want member. I remember thinking Consulting” and we conclude to thank Fabrizio Ruggeri for I’ll never be able to do this. I the Student’s Corner with the many useful suggestions and can’t even turn in an assignment abstract of the thesis of Dr. D. for all the support he has offered in my applied statistics course Conesa. My main goal was to me and all the recent Ph.D.’s without at least a couple of fatal present different topics which who have helped me with their errors in my analysis. are interesting for all students, articles and thesis’ abstracts. Somewhere between that time and I hope I have, at least and now, I’ve become the partially, fulfilled it. Still I Director of the Statistical

18 ISBA Bulletin, December 2000 STUDENT’S CORNER

Consulting Center at Duke yourself and do your own progress on the problem? How University. original work. This is the much work will it take? How It turns out that working as a absolute worst thing you can do much should I charge? Can it be statistical consultant is nothing as a consultant. Use your smart done in time? Should I try to get like carrying out data analyses colleagues. Buy them a coffee a grad student to do it? Nothing in a virtual vacuum as I did and pick their brains. Nothing beats experience for deciding on when I was in graduate school. beats discussing the problem the above questions. Below are Your success as a consultant and getting a clearer idea of some items I try to keep in mind more often depends on how what should be done. Be sure when dealing with a client. well you can pry ideas out of not to wear out your best Many of these items are taken others. The job has a lot of resources by bugging them too from Brian Joiner’s article on perks. First, you get to be part of much. statistical consulting. interesting research in a range of • Be fun to talk to. If consulting • Listen a lot different disciplines. Better yet, with you is a painful experience, you get to be part of the action • Never (almost never) even great advice and analysis interrupt the client as an equal with the researchers. may not be enough to get them Of course we all know the top to pay for your services again. • Always (almost always) perk is that as a statistical allow the client to interrupt you consultant, you impress at • Know lots of methods. You’ll • Ask lots of questions that parties. Unlike the dreaded be less likely to fit the problem begin “Let me see if I words “I’m a statistician” which to an inappropriate method. But understand this,. . . .” repel with the strength of mild don’t worry that you don’t body odor, saying “I’m a know it all. You never will, but • Try not to meet right as statistical consultant” can often you probably know enough. you’re getting back from your entice people to speak to you. • Stay in contact with the afternoon jog. Alternatively, That classic pickup line started faculty and your fellow students. look good, and smell good. off a couple of consulting They’re possibly your most • Take good notes. relationships for me. valuable resource as a • Try to avoid statistical So, if you think you might be consulting statistician. interested in consulting, I’ve jargon. Use common, simple • Be one with the computer. listed some tips for those in words whenever possible. Learn to deal with data in all grad school, or just starting out. • At the end of the meeting, forms. Many interesting jobs Don’t worry, most of the points put down in writing what is to I’ve had began with a somewhat below aren’t mine. I’ve collected be done next. painful data formatting and them from others while in grad cleansing stage. Had I not been • Interact frequently with the school and while working at willing to mess with the original client. Don’t go off and do a lot ISDS. This first list is a collection ugly data, I never would have of work at the client’s expense of rather general info. gotten these jobs. (or worse, yours) without • Take on some consulting while Generally, my first meeting discussing approaches and you’re still a student. It looks with a client is devoted to trying intermediate results. great on the cv and it will give to understand the client’s • Make realistic cost estimates you some experience. If you get problem and what sort of data (in currency and/or time) and stuck, you’re surrounded by they have to address it. Very discuss them. students and faculty who can rarely do I actually think about help out. methods this first time meeting. • Be timely. An approximate answer in a few days is almost • Get help from brains around After the initial meeting, I’ll always preferable to an “exact” you. Get their advice. typically ponder such questions answer months (or years, in one Consulting is unlike as: Do I want to get involved in of my jobs) later. coursework. Don’t isolate this? Can I actually make

19 ISBA Bulletin, December 2000 STUDENT’S CORNER

• If it’s possible, try to meet at • Once in a while, someone of the number of customers in the client’s office. He or she will will drop in merely wanting the system through its feel more at ease. Also, you may their results sanctified by probability generating function, be able to get a better idea of the having you sprinkle the holy and the posterior distribution of project you are about to water of statistical significance the waiting time, in the queue undertake. levels over them. Be sure to and in the system, of the first charge a lot, or they won’t feel customer of an arriving group Finally, consulting gives you a their results are truly sanctified. in terms of their Laplace and healthy perspective about the • A good answer to the Laplace-Stieltjes transform. place of statistics in science. As question “How much is this Discussion of numerical a statistician, you’re unlikely to going to cost?” is “How much inversion of these transforms is ever be in a position to make do you have?” addressed. discoveries that change the way Next, we use a Hierarchical people see the world. However, • If you can’t answer the Bayesian model to study the through consulting, you can be clients question with the data general situation of the a very important contributor to they provided, then find congestion of a system formed important scientific research. Of something you can answer with by K M/M(a, b)/1 bulk service course the cynics out there the data and convince the client queues working in equilibrium might put it another way: You that you actually answered the and independently between won’t discover life on other question of interest. them. In this case, in order to planets; you’ll help shed light make inference on the on whether or not all aspirin is David Conesa parameters governing all this really alike. Whichever way you [email protected] system, and in order to evaluate see it, being a part of such Inference and prediction in bulk the posterior predictive collaborations should keep us arrival queues and bulk service distribution of the most relevant statisticians humble. For the queues. measures of performance, we finale, I leave you with the Advisor: Dr. Carmen Armero use procedures based on cynical consultant’s tips of the In this thesis we analyze, from a Markov Chain Monte Carlo trade. Bayesian point of view, the two integration jointly with • If your particular consulting most standard bulk queueing algorithms for numerical project is becoming drudgery, systems. We begin reviewing inversion of transforms. try doubling your consulting the use of statistics in queues. Finally, we include two rate. Then, we study a system in appendixes. In the first one, we which customers arrive in bulks review the most basic properties • If a client would like you to of variable size, usually of the queueing systems we do a sample size calculation, represented in Queueing Theory work with in the memory, while they must be working on a by M X /M/1. Our focus is on in the second one, we describe grant proposal. Hold out until prediction of the usual measures in detail the algorithms used for they agree to write in a nice of performance of this system in numerical inversion of chunk of change in the grant equilibrium. We obtain the transforms. budget for you. posterior predictive distribution

BULLETIN BY E-MAIL SENDINGAMESSAGETO [email protected], SPECIFYINGTHE PREFERRED FORMAT (POSTSCRIPT, COMPRESSED POSTSCRIPTOR PDF)

20 ISBA Bulletin, December 2000 BIBLIOGRAPHY

ECONOMETRICS:AN look for recent BLAUG (EDS.), (1997). ANNOTATED developments and survey articles. Bayesian Analysis in BIBLIOGRAPHY ➤ Bayesian Foundations Econometrics and Statistics: The Zellner View and Papers. by Jeffrey Mills and • A.ZELLNER (1971). An Economists of the Twentieth Siva Sivaganesan Introduction to Bayesian Century, Edward Elgar Publishing. [email protected] Inference in Econometrics. J. Given above are two collections [email protected] Wiley and Sons, Inc., New York. of Zellner’s papers in nice tidy Reprinted in Wiley Classics, 1996. We focus on Applications books. Saves you all the time Thirty years later and we are and effort you would have to using MCMC, BVARs, Unit still begging for a second edition, Root Debate, Bayesian spend individually hunting but how could he improve it?! down these masterpieces in Foundations, and Exam- An absolute must read. ples and Applications dusty libraries. How much is • E.E.LEAMER (1978). Arnold paying us you say? Not Specification Searches: Ad Hoc a cent (and we’ve lost a lot of Arnold Zellner is, without Inference with Nonexperimental money betting on him for a doubt, the Father of Bayesian Data. Wiley, New York. Nobel over the years too)! Buy econometrics. If one were to The “other” classic. Also a these books, read them, put construct a family tree of must read. There is still much them under your pillow at night Bayesian econometrics papers gold to be mined from this one too. and hope that somnolent and books, there would be at osmosis works. You can find least several offspring from each The following article provides more recent papers by Zellner at generation, but they all would an introduction to the subjective his homepage: gsb.uchicago.edu/ originate from Zellner’s 1970 Bayesian approach intended for fac/arnold.zellner/ seminal text. In Bayesian novices, with discussion by a econometrics, it is safe to say believer and two heathens. • D.J.POIRIER (1995). that all roads lead to Arnold • D.J.POIRIER (1988). Intermediate Statistics and Zellner! It is also accurate to Frequentist and Subjectivist Econometrics: A Comparative state that by now, almost all Perspectives on the Problems Approach. MIT Press, Cambridge. quantitative problems in of Model Building in In the author’s own words: economics and econometrics Economics (with discussion). “The above text is an have been analyzed from the Journal of Economic Perspectives, 2 introduction to mathematical Bayesian point of view, and (Winter), 121-170. statistics and the linear regression model for students results compared to those • A.ZELLNER (1988). pursuing research careers in provided by non-Bayesian Bayesian Analysis in economics. Its distinguishing procedures. Therefore this Econometrics. Journal of feature is its broad perspective survey can, at best, only be a Econometrics. 37, 27-50. that develops in parallel both perfunctory one. Our goal has Arnold throws down the classical and Bayesian been to try and provide enough gauntlet and issues specific treatments of topics. The clues that, by starting with this challenges to non-Bayesians. As primary intended reader of this brief review, the reader should far as we know, as yet no one has text is a first-year Ph.D. student be able to track down the been willing to step out of the in economics. It is important current literature on any saloon and try to shoot holes in that a text is immediately Bayesian econometrics topic his argument (is Clint Eastwood accessible to its primary with a minimal amount of a Bayesian we wonder?). effort. Recent issues of Journal of intended audience. This text • A.ZELLNER (1984). Basic assumes the minimal Econometrics, Journal of Business Issues in Econometrics. and Economic Statistics, mathematical background University of Chicago Press, demanded for admittance to Econometrica, Journal of Applied Chicago. Reprinted in 1987. Econometrics, and Econometric most graduate programs in • M.PERLMANAND M. Reviews are also a good place to economics.”

21 ISBA Bulletin, December 2000 BIBLIOGRAPHY

➤ MCMC and Monte Tailored MCMC algorithms Econometrica, 64, 381-412. Carlo Integration Methods are given for posterior This paper develops a general simulation in longitudinal asymptotic theory of Bayesian • S.CHIBAND E. Poisson data mod- inference for time series. GREENBERG (1996).Markov Chain Monte Carlo Simulation els with multiple random effects. • J.ALBERTAND S.CHIB Methods in Econometrics. Chib’s (1995) approach is adapted (1993). Bayesian Analysis via Econometric Theory, 12, 409-431. to find the model marginal Gibbs Sampling of likelihood and Bayes factors. Autoregressive Time Series • J.GEWEKE (1997). Posterior Simulators in • J.GEWEKE (1989). Subject to MarkovMean and Econometrics. Advances in Bayesian Inference in Variance Shifts. Journal of Economics and Econometrics: Econometric Models Using Business and Economic Statistics, Theory and Applications. Seventh Monte Carlo Integration. 11, 1-15. World Congress, volume III. D.M. Econometrica, 57, 1317-1339. In this paper, analysis of Kreps and K.F. Wallis (eds.), 128- • T. KLOEKAND H.K. VAN hidden Markov time series from 165. DIJK (1978). Bayesian a Bayesian perspective is The above two papers Estimates of Equation System presented. A MCMC approach provide an excellent review of Parameters: An Application of is developed and used to find the literature in this area. Integration by Monte Carlo. the posterior distribution of the Econometrica, 46, 1-19. hidden states, future • S.CHIB (1992). Bayes observations and residuals. Inference in the Tobit The above two papers are the Censored Regression Model. classics on Monte Carlo integration • J.WANGAND E.ZIVOT Journal of Econometrics, 51, 79-99. methods in econometrics. (2000). A Bayesian Time Series A MCMC method for fitting ➤ Time Series Methods Model of Multiple Structural the Tobit model under both Changes in Level, Trend, and The Bayesian approach to Variance. Journal of Business and Gaussian and student-t time series in econometrics has assumptions is given. Proposed Economic Statistics, 18, 374-386. become increasingly popular in The above paper addresses approach is compared with recent years. See, for example, alternative Bayesian estimation the effects of structural breaks the two recent themed issues of on inference in time series. techniques. the Journal of Applied • G.KOOPAND S.M.POTTER • S.CHIB (1996). Calculating Econometrics (1991) and (1999). Bayes Factors and Posterior Distributions and Econometric Theory (1994). Modal Estimates in Markov Nonlinearity: Evidence From • S.CHIBAND E. Mixture Models. Journal of Economic Time Series. Journal GREENBERG (1994). Bayes Econometrics, 75, 79-97. of Econometrics, 88, 251-281. Inference in Regression This paper considers the A new analysis of hidden Models with ARMA (p,q) Markov models using MCMC Bayesian approach to Errors. Journal of Econometrics, evaluating nonlinearity in time methods is presented. Also 64, 183-206. includes a discussion of modal series, and contains a nice An approach for fitting time survey of recent literature. estimation. Applications to series models using tuned • M.BILLIO,A.MONFORT Poisson data, mixtures of MCMC methods is developed. multivariate normal A., AND C.P. ROBERT (1999). The paper also shows how the Bayesian estimation of distributions, and autoregressive main algorithm can be specialized time series are given. switching ARMA models. for special cases of the model. Journal of Econometrics, (93)2, • S.CHIB,E.GREENBERG Several examples of the 229-255. AND R.WINKELMANN (1998). methods in action are presented. Posterior Simulation and Bayes This paper gives a Bayesian • P.C.B. PHILLIPSAND W. Factors in Panel Count Data MCMC approach for switching PLOBERGER (1996). An Models. Journal of Econometrics, ARMA models with a Asymptotic Theory of Bayesian non-informative prior distribution. 86, 33-54. Inference for Time Series.

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• T.S. SHIVELY AND R.KOHN Econometric Theory, 10, 645-671. Zellner. Wiley, New York. (1997). A Bayesian approach to • D.N.DEJONGAND C.H. This book is a collection of model selection in stochastic WHITEMAN (1993). Estimating recent papers on a variety of coefficient regression models Moving Average Parameters: topics. and structural time series models. Classical Pileups and Bayesian • B.M.HILL (1986) Some J. Econometrics, (76)1-2, 39-52. Posteriors. Journal of Business Subjective Bayesian A Bayesian model selection and Economic Statistics, 11, 311-317. Considerations in the Selection procedure is presented for a • J.KADANE,N.H.CHAN of Models (with discussion). stochastic coefficient regression AND L.J.WOLFSON (1996). Econometric Reviews, 4, 191-288. model to determine which Priors for unit root models. • D.N.DEJONG, B.F. coefficients are fixed and which Journal of Econometrics, (75)1, INGRAMAND C.H.WHITEMAN are time-varying. 99-111. (1996). A Bayesian Approach ➤ Bayesian Vector This paper presents a method to Calibration. Journal of Autoregressions (BVARs) of assessing the subjective prior Business and Economic Statistics, for a unit root model based on a 14, 1-9. • T. DOAN,R.LITTERMAN family of piecewise conjugate The above article gives a AND C.A.SIMS (1984). prior distributions. Bayesian approach to Forecasting and Conditional “calibrating” macroeconomic Projection using Realistic Prior ➤ Econometrics Software models. Distributions. Econometric • G.KOOP (1999). Bayesian • J.H.DREZEAND J.-F. Reviews, 3, 1-100. Analysis, Computation and RICHARD (1983). Bayesian • K.R.KADIYALA AND S. Communication Software. Analysis of Simultaneous KARLSSON (1997). Numerical Journal of Applied Econometrics, Equations Systems. In: Methods for Estimation and 14, 677-689. Handbook of Econometrics, Z. Inference in Bayesian VAR This paper focuses mainly on Griliches and M. D. Intriligator, Models. Journal of Applied a review of BACC, a new eds., Vol. 1 (North-Holland), Econometrics, 12, 99-132. Bayesian software package 517-598. • H.UHLIG (1997). Bayesian which is linked to GAUSS and This is an excellent reference Vector Autoregressions with takes the form of a set of source for the state of Bayesian Stochastic Volatility. GAUSS commands. analysis of simultaneous Econometrica, 65, 59-73. GAUSS currently appears to equation models There are also numerous be the most popular software as of the early 1980s, pre-MCMC. for Bayesian econometric articles in the Minnesota Federal • J.A.MILLS (1992). analysis. Though one should Reserve Review relating to BVARs. Bayesian Prediction Tests for take note of the following review: ➤ The Unit Root Debate Structural Stability. Journal of • H.D.VINOD (2000). Econometrics, 52, 381-388. • C.A.SIMSAND H.UHLIG Review of GAUSS for A paper worth reading or just (1991). Understanding Unit Windows, Including its shameless self-promotion? The Rooters: A Helicopter Tour. Numerical Accuracy. Journal of second author thinks it is the Econometrica, 59, 1591-1600. Applied Econometrics, 15, former. Read and decide for • P.C.B. PHILLIPS (1991). To 211-220. yourself! Criticize the Critics: An ➤ A Small Sampling of • T. FOMBYAND R.CARTER Objective Bayesian Analysis of Other Bayesian HILL(EDS.) (1996). Advances Stochastic Trends. Journal of Econometrics Topics in Econometrics, Volume 10 A Applied Econometrics, 6, 333-364. • D.BERRY,K.CHALONER and B. JAI Press, Greenwich. • H.UHLIG (1994). What AND J.GEWEKE(EDS.), (1996). These two books contain a Macroeconomists Should bf Bayesian Analysis in number of papers on methods Know About Unit Roots: A Statistics and Econometrics: and applications by authors Bayesian Perspective. Essays in Honor of Arnold such as J. Albert, J-F. Angers, L.

23 Bauwens, S. Chib, P. Cook, D. K. Dey, A.E. Gelfand, W.E. Griffiths,

24 ISBA Bulletin, December 2000 BIBLIOGRAPHY

A. Gelman, J. Kadane, M. Statistics, 9 (April), 125-148. Journal of Econometrics, (96)2, Lubrano, A. Pole and H. This study investigates the 293-356. Tsurumi. empirical evidence on the This article uses data from the ➤ Empirical Applications effects of unanticipated changes Panel Survey of Income Dynamics of Bayesian Methods in nominal money on real (PSID) to address a number of output in 47 countries when questions about life cycle • S.E.PAMMER,D.K.H. viewed through a window (i.e., earnings mobility from a FONG, S.F. ARNOLD (2000). likelihood function) that Bayesian dynamic reduced form Forecasting the Penetration of a assumes the neutrality of model of earnings and marital New Product - A Bayesian anticipated changes. Using a status. Approach. Journal of Business Bayesian predictivist approach, • D.J.POIRIER, ED. (1991). and Economic Statistics, 18, it provides a pedagogical Bayesian Empirical Studies in 428-435. Bayesian analysis of generated Economics and Finance. Annals • P.J. DESCHAMPS (2000). regressor models in the face of of the Journal of Econometrics, 49, Exact Small-Sample Inference specification uncertainty 1-2 (July/August). in Stationary, Fully Regular, involving, among other things, This is a collection of serious Dynamic Demand Models. multiple unit roots and trend Bayesian empirical papers at a Journal of Econometrics, 97, 51-91. stationary alternatives. time when such things were • G.M.ALLENBYAND P.E. • G.KOOP, AND D.J. relatively scarce in the ROSSI (1999). Marketing POIRIER (1995). An Empirical econometrics literature. Models of Consumer Investigation of Wagner’s More recently, work by J. Heterogeneity. Journal of Hypothesis by Using a Model Quintana, B. Putnam, M. West Econometrics, 89, 57-78. Occurrence Framework Journal and their colleagues on • D.N.DEJONG, B.F. of the Royal Statistical Society, Bayesian optimal portfolio INGRAM, AND C.H. Series A, 158, 123-141. analyses that have appeared in WHITEMAN (2000). Keynesian Based on data from eighty-six the ASA’s SBSS Proceedings Impulses Versus Solow countries, this study employs a volumes since the early 1990s Residuals: Identifying Sources model occurrence framework to give a good account of how of Business Cycle Fluctuations. obtain empirical applicability Bayesian analysis is being used Journal of Applied Econometrics, conditions that generically on Wall Street by certain 15, 311-329. determine the prior probability investment companies. • D.J.POIRIERED. (1991). of Wagner’s Hypothesis, given Special thanks to Dale Poirier Bayesian Empirical Studies in individual country and Arnold Zellner for many Economics and Finance. Annals characteristics, for five helpful suggestions. Our of the Journal of Econometrics, 49, out-of-sample countries. apologies to the authors of the Nos. 1-2 (July/August). • M.WEST (1996). Inference many serious ommissions that The above is a collection of in successive sampling were either forced upon us in serious Bayesian empirical discovery models. Journal of the interest of brevity, or were a papers at a time when such Econometrics, (75)1, 217-238. result of our own ignorance. things were relatively scarce in A super-population Bayesian The second author would also the econometrics literature. framework is preented for the like to express his deep gratitude to Wolfgang Polasek • D.J.POIRIER (1991). A analysis of successive sampling for his valuable help with the Bayesian View of Nominal discovery problems that arise in Bibliography on Finance that Money and Real Output finite population sampling appeared in the previous Through a New Classical subject to ‘size-biased’ selection edition of the ISBA Bulletin. Macroeconomic Window (with mechanisms. Wolfgang Polasek provided discussion). JBES invited paper • J.GEWEKEAND M.KEANE most of the references in that for the 1990 ASA Meetings. (2000). An empirical analysis issue, where he should have Journal of Business & Economic of earnings dynamics among men in the PSID: 1968–1989. appeared as an author.

25 ISBA Bulletin, December 2000 NEWS FROM THE WORLD

NEWSFROMTHE quantum probability and Forecasts, Robust Modelling in WORLD statistics, statistical mechanics, Finance, Value at Risk, and statistics of extremes, Introduction to Financial by Antonio Pievatolo telecommunications, and time Econometrics. Web page of the [email protected] series. Submit your papers by course: www.unibas.ch/iso/ March 1, 2001. Web page: ECAS2001. ✽ denotes an ISBA activity www.fc.ul.pt/cea/ems2001. ➤ ➤ Research Opportunities Events Summer School on Spatial Statistics and Computational Open positions in New Gordon Research Methods. August 19-22, 2001, Zealand. Conference on Statistics in Aalborg University, Denmark. ∗ Academic Biostatistician Chemistry and Chemical The purpose of this summer University of Otago. This is a Engineering. July 22-27, 2001, school is to train young full-time confirmation path Williamstown, MA, USA. postdocs and Ph.D. students in (tenure track) position in the This conference focuses on recent advances in spatial Department of Preventive and new research directions in statistics and computational Social Medicine. Applicants applied statistics and the methods. The programme should have a doctoral degree analysis of chemical features four courses: Theory in biostatistics, statistics, or a phenomena; it has met annually and practice of MCMC; closely related discipline, and for half a century. Typically, Model-based geostatistics; appropriate experience. The readers of the Journal of Simulation based inference for salary range for a Lecturer is Chemometrics, Chemometrics spatial point processes; Image NZ$46,350 to NZ$57,165 per and Intelligent Laboratory analysis. Apply before April 1, annum. Please contact Dr. John Systems, and Applied 2001. Web page: www.math. Kittelson Spectroscopy are a part of the auc.dk/~mbh/SS-and-CM2001/. ([email protected]). audience. Web page: ∗ Dynamic Sports Enthusiasts www.asaspes.org/GRC2001.htm. ECAS course on Bayesian Massey University. In Statistics and Financial conjunction with industry the 23rd European Meeting of Econometrics. October 7-13, Institute of Information and Statisticians. August 13-19, 2001, Lugano, Switzerland. Mathematical Sciences (IIMS) at 2001, Funchal, Madeira. ECAS (European Courses in Massey University’s Auckland The Programme Committee Advanced Statistics) is a campus is developing a has prepared invited papers programme supported by the post-graduate program for sessions on many topics of main statistical societies of Statistics graduates who are current interest in statistics and Europe. So far, the programme interested in analysing and probability. The keynote has organized seven courses in presenting information relating lectures are on “Some statistical as many European countries. to sports. Submit your CV’s to challenges in modern genetics”, This ECAS course will give an Denny Meyer on “Polymer chains” and on introduction into recent ([email protected]). “Information theory in advances of estimation ∗ Senior Analyst New Zealand probability and statistics”. techniques for complex models Ministry of Agriculture and There will be invited paper and will demonstrate financial Forestry. The position involves sessions on asymptotic modelling strategies that have overseeing the collection, statistics, Bayesian become important in recent analysis and publication of a nonparametrics, bioinformatics, years. The following topics will broad range of primary causal inference, concentration be treated: Bayesian Statistics production statistics and of measure, disease mapping, with MCMC, Bayesian Financial includes the ongoing environmetrics, finance, perfect Modelling using BACC, management of the collection of simulation, probability Bayesian financial data mining, Agricultural Statistics. The ideal approximations for rare events, Portfolio Selection with GARCH

26 ISBA Bulletin, December 2000 NEWS FROM THE WORLD candidate would have a ➤ Awards and Prizes nominee, nominator (if different) relevant post graduate and evaluators noted above. qualification and must have ✽ The 2001 Mitchell Prize. practical experience in the The Mitchell Prize committee ➤ Miscellanea following areas: application of would like to invite quantitative information to nominations for this year’s ICSC/NAISO. policy advice and development; Mitchell Prize. The Prize is International Computer primary production statistical awarded in recognition of an Science Conventions (ICSC) is a inventories, trade statistics and outstanding paper that non-profit making national accounts; statistical describes how a Bayesian multinational association collection systems; quality analysis has solved an interested in development of management of quantitative important applied problem. The science and technology. The outputs; publication of Prize includes an award of objects of Natural and Artificial quantitative information. For a $1000 and a commemorative Intelligence Systems job description please contact plaque. The 2001 Prize selection Organization (NAISO) are the Kim Mulu, MAF Policy, committee members are Gary encouragement of efficient [email protected]; For further Koop (chair), Henry Wynn and communication between details about the position please Rod Little. scientists, researchers, engineers contact Paul Lane, MAF Policy, Eligible papers must be and practitioners in the field of [email protected]. published (or forthcoming) in a natural and artificial intelligence ∗ PhD Student University of refereed journal or conference systems. ICSC/NAISO Canterbury. Phenomenological proceedings no earlier than organizes many conferences on data collection methods, January 1, 1999. Entries must be topics related to Computer structural equation modeling received by February 1, 2001. Science. Those Bayesians who and multivariate analysis will Complete details about the work on subjects that border it be used to understand how Prize and the nomination (such as Image Analysis) might wood products, used for process are provided in the want to look at ICSC/NAISO interior and environmental Mitchell Prize Charter web page: www.icsc.ab.ca. design, can impact both (www.bayesian.org/ BayStat. physical and emotional awards/mitchellcharter.html). Recently established in Italy, wellbeing. The position will A complete entry consists of the BayStat promotes the also involve significant following: application of statistical interaction with Forest Research ∗ four copies of the methodology, especially (New Zealand Forest Research manuscript or reprint being Bayesian, in business and Institute), who are an nominated; economics. This task is internationally recognised ∗ a brief statement by the accomplished through the supplier of research and nominator describing the organisation of meetings, technological development to impact of the work (authors workshops and, more generally, the forestry and forest products may nominate themselves); research and teaching, scientific sector. Funding is available for ∗ names of two evaluators, publications, collaborations three years. Applicants should not the nominator or coauthors, with national and international be presented by three referees. who are willing and able to companies and institutions. The For further infor- credibly evaluate the usefulness first conference was entitled mation contact Dr. Irene Hudson of the work from the “Statistical Models for Data ([email protected]. perspective of the applied field Mining”; the second one, nz) or Dr. Brad Ridoutt addressed in the paper as “Statistics for (brad.ridoutt@ distinct from providing Telecommunications”, is forestresearch.co.nz). comments on its statistical merit; planned for July 2001. Web ∗ contact information for page: www.baystat.it.

27 ISBA Bulletin, December 2000 MEMBERSHIP SUBSCRIPTION 2001

JOININGANDREJOINING ISBA

As laid down in Section G of the by-laws (viewable on the ISBA web site at http://www.bayesian.org), the ISBA membership subscription for 2001 falls due on 1 January 2001. The fee can be paid through the web site, or by completing this form and returning it to:

Professor Valen Johnson, ISBA Treasurer voice: +1-919-684-8753 Institute of Statistics & Decision Sciences fax: +1-919-684-8594 223 Old Chem Building e-mail: [email protected] Box 90251 web: http://www.isds.duke.edu/~valen/ Duke University Durham, NC USA 27708-0251

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28 ISBA Bulletin, December 2000 ISBA OFFICERS

Executive Committee Program Council Board Members

Deborah Ashby, Mark Berliner, Pet- President: Philip Dawid Chair: Edward George ros Dellaportas, Dani Gamerman, Past President: John Geweke Vice Chair: Anthony O’Hagan Alan Gelfand, Jayanta Ghosh, Jay President Elect: Alicia Carriquiry Past Chair: Robert Wolpert Kadane, Rob Kass, Luis Pericchi, Treasurer: Valen Johnson Sylvia Richardson, Dalene Stangl, Executive Secretary: Michael Evans Mark Steel § ¤ Web page: http://www.bayesian.org/ ¦ ¥

EDITORIAL BOARD

Editor

Fabrizio Ruggeri

Associate Editors Corresponding Editors

Students’ Corner Carmen Armero Maria De Iorio Marilena Barbieri Applications Christopher Carter Sujit Ghosh Roger M. Cooke Petros Dellaportas Software Review Eduardo Gutierrez Pena˜ Gabriel Huerta Robert Kohn Jack C. Lee News from the World Leo Knorr-Held Antonio Pievatolo Udi Makov Marek Me¸czarski Bayesian History Renate Meyer Raquel Prado Suleyman Ozekici Wolfgang Polasek Interviews Jose´ Miguel Perez David Rios Insua Josemar Rodrigues Michael Wiper Alfredo Russo Annotated Bibliography Antonia Amaral Turkman Siva Sivaganesan Brani Vidakovic Mattias Villani Bayesian Teaching Hajime Wago Dalene Stangl Simon Wilson Lara Wolfson Karen Young

 Mailing address: ISBA Bulletin - CNR IAMI - Via Amp`ere 56 - 20131 Milano (Italy) E-mail: [email protected] Phone: +39 0270643206 Fax: +39 0270643212 Web page: http://www.iami.mi.cnr.it/isba 

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