The Stata Journal Volume 17 Number 4 2017 ® ® A Stata Press publication StataCorp LLC College Station, Texas The Stata Journal Editors H. Joseph Newton Nicholas J. Cox Department of Statistics Department of Geography Texas A&M University Durham University College Station, Texas Durham, UK
[email protected] [email protected] Associate Editors Christopher F. Baum, Boston College Ulrich Kohler, University of Potsdam, Germany Nathaniel Beck, New York University Frauke Kreuter, Univ. of Maryland–College Park Rino Bellocco, Karolinska Institutet, Sweden, and Peter A. Lachenbruch, Oregon State University University of Milano-Bicocca, Italy Jens Lauritsen, Odense University Hospital Maarten L. Buis, University of Konstanz, Germany Stanley Lemeshow, Ohio State University A. Colin Cameron, University of California–Davis J. Scott Long, Indiana University Mario A. Cleves, University of Arkansas for Roger Newson, Imperial College, London Medical Sciences Austin Nichols, Abt Associates, Washington, DC William D. Dupont , Vanderbilt University Marcello Pagano, Harvard School of Public Health Philip Ender , University of California–Los Angeles Sophia Rabe-Hesketh, Univ. of California–Berkeley David Epstein , Gerson Lehrman Group J. Patrick Royston, MRC CTU at UCL, London, UK Allan Gregory , Queen’s University Mark E. Schaffer, Heriot-Watt Univ., Edinburgh James Hardin , University of South Carolina Jeroen Weesie, Utrecht University Ben Jann , University of Bern, Switzerland Ian White, MRC CTU at UCL, London, UK Stephen Jenkins , London School of Economics and Nicholas J. G. Winter,UniversityofVirginia Political Science Jeffrey Wooldridge, Michigan State University Stata Press Editorial Manager Stata Press Copy Editors Lisa Gilmore Adam Crawley, David Culwell,andDeirdre Skaggs The Stata Journal publishes reviewed papers together with shorter notes or comments, regular columns, book reviews, and other material of interest to Stata users.