Causality: Rubin (1974)
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Causal Inference with Information Fields
Causal Inference with Information Fields Benjamin Heymann Michel De Lara Criteo AI Lab, Paris, France CERMICS, École des Ponts, Marne-la-Vallée, France [email protected] [email protected] Jean-Philippe Chancelier CERMICS, École des Ponts, Marne-la-Vallée, France [email protected] Abstract Inferring the potential consequences of an unobserved event is a fundamental scientific question. To this end, Pearl’s celebrated do-calculus provides a set of inference rules to derive an interventional probability from an observational one. In this framework, the primitive causal relations are encoded as functional dependencies in a Structural Causal Model (SCM), which maps into a Directed Acyclic Graph (DAG) in the absence of cycles. In this paper, by contrast, we capture causality without reference to graphs or functional dependencies, but with information fields. The three rules of do-calculus reduce to a unique sufficient condition for conditional independence: the topological separation, which presents some theoretical and practical advantages over the d-separation. With this unique rule, we can deal with systems that cannot be represented with DAGs, for instance systems with cycles and/or ‘spurious’ edges. We provide an example that cannot be handled – to the extent of our knowledge – with the tools of the current literature. 1 Introduction As the world shifts toward more and more data-driven decision-making, causal inference is taking more space in applied sciences, statistics and machine learning. This is because it allows for better, more robust decision-making, and provides a way to interpret the data that goes beyond correlation Pearl and Mackenzie [2018]. -
1 the University of Chicago the Harris School of Public
THE UNIVERSITY OF CHICAGO THE HARRIS SCHOOL OF PUBLIC POLICY PPHA 421: APPLIED ECONOMETRICS II Spring 2016: Mondays and Wednesdays 10:30 – 11:50 pm, Room 140C Instructor: Professor Koichiro Ito 157 Harris School [email protected] Office hours: Mondays 3-4pm TA: Katherine Goulde: [email protected] Course Description The goal of this course is for students to learn a set of statistical tools and research designs that are useful in conducting high-quality empirical research on topics in applied microeconomics and related fields. Since most applied economic research examines questions with direct policy implications, this course will focus on methods for estimating causal effects. This course differs from many other econometrics courses in that it is oriented towards applied practitioners rather than future econometricians. It therefore emphasizes research design (relative to statistical technique) and applications (relative to theoretical proofs), though it covers some of each. Prerequisites PPHA42000 (Applied Econometrics I) is the prerequisite for this course. Students should be familiar with graduate school level probability and statistics, matrix algebra, and the classical linear regression model at the level of PPHA420. In the Economics department, the equivalent level of preparation would be the 1st year Ph.D. econometrics coursework. In general, I do not recommend taking this course if you have not taken PPHA420: Applied Econometrics I or a Ph.D. level econometrics coursework. This course is a core course for Ph.D. students and MACRM students at Harris School. Those who are not in the Harris Ph.D. program, the MACRM program, or the economics Ph.D. program need permission from the instructor to take the course. -
Donald Rubin Three-Day Course in Causality 5 to 7 February 2020 At
Donald Rubin Three-day Course in Causality 5 to 7 February 2020 at Waldhotel Doldenhorn, Kandersteg About the Course Most questions in social and biomedical sciences are causal in nature: what would happen to individuals, or to groups, if part of their environment were changed? In the course, the world-renowned expert Donald Rubin (Prof. em. Harvard) presents statistical methods for studying such questions. The course will follow his book Causal Inference for Statistics, Social, and Biomedical Sciences (Cambridge University Press, 2016) and starts with the notion of potential outcomes, each corresponding to the outcome that would be realized if a subject were exposed to a particular treatment or regime. In this approach, causal effects are comparisons of such potential outcomes. The fundamental problem of causal inference is that we can only observe one of the potential outcomes for a particular subject. Prof. Rubin will discuss how randomized experiments allow us to assess causal effects and then turn to observational studies. They lay out the assumptions needed for causal inference and describe the leading analysis methods, including matching, propensity-score methods, and instrumental variables. Many detailed applications will be shown, with special focus on practical aspects for the empirical researcher. About the Lecturer Donald B. Rubin is Professor Emeritus of Statistics, Harvard University, where he has been professor from 1984 to 2018 and department chair for fifteen years. Since 2018 he is professor at the Yau Mathematical Sciences Center, Tsinghua University, China, and Murray Shusterman Senior Research Fellow at the Department of Statistical Science, Fox School of Business, Temple University, Philadelphia. -
Theory with Applications to Voting and Deliberation Experiments!
Randomized Evaluation of Institutions: Theory with Applications to Voting and Deliberation Experiments Yves Atchadey and Leonard Wantchekonz June 24, 2009 Abstract We study causal inference in randomized experiments where the treatment is a decision making process or an institution such as voting, deliberation or decentralized governance. We provide a statistical framework for the estimation of the intrinsic e¤ect of the institution. The proposed framework builds on a standard set-up for estimating causal e¤ects in randomized experiments with noncompliance (Hirano-Imbens-Rubin-Zhou [2000]). We use the model to re- analyze the e¤ect of deliberation on voting for programmatic platforms in Benin (Wantchekon [2008]), and provide practical suggestions for the implementation and analysis of experiments involving institutions. 1 Introduction Randomized experiments are a widely accepted approach to infer causal relations in statis- tics and the social sciences. The idea dates back at least to Neyman (1923) and Fisher (1935) and has been extended by D. Rubin and coauthors (Rubin (1974), Rubin (1978), Rosenbaum and Rubin (1983)) to observational studies and to other more general experimental designs. In this approach, causality is de…ned in terms of potential outcomes. The causal e¤ect of a treatment, say Treatment 1 (compared to another treatment, Treatment 0) on the variable Y and on the statistical unit i is de…ned as Y i(1) Y i(0) (or its expected value) where Y i(j) is the value we would observe on unit i if it receives Treatment j. The estimation of this e¤ect is problematic because unit i cannot be given both Treatment 1 and Treatment 0. -
Arxiv:1805.08845V4 [Stat.ML] 10 Jul 2021 Outcomes Such As Images, Sequences, and Graphs
Counterfactual Mean Embeddings Krikamol Muandet∗ [email protected] Max Planck Institute for Intelligent Systems Tübingen, Germany Motonobu Kanagaway [email protected] Data Science Department, EURECOM Sophia Antipolis, France Sorawit Saengkyongam [email protected] University of Copenhagen Copenhagen, Denmark Sanparith Marukatat [email protected] National Electronics and Computer Technology Center National Science and Technology Development Agency Pathumthani, Thailand Abstract Counterfactual inference has become a ubiquitous tool in online advertisement, recommen- dation systems, medical diagnosis, and econometrics. Accurate modelling of outcome distri- butions associated with different interventions—known as counterfactual distributions—is crucial for the success of these applications. In this work, we propose to model counter- factual distributions using a novel Hilbert space representation called counterfactual mean embedding (CME). The CME embeds the associated counterfactual distribution into a reproducing kernel Hilbert space (RKHS) endowed with a positive definite kernel, which allows us to perform causal inference over the entire landscape of the counterfactual distri- bution. Based on this representation, we propose a distributional treatment effect (DTE) which can quantify the causal effect over entire outcome distributions. Our approach is nonparametric as the CME can be estimated under the unconfoundedness assumption from observational data without requiring any parametric assumption about the underlying dis- tributions. We also establish a rate of convergence of the proposed estimator which depends on the smoothness of the conditional mean and the Radon-Nikodym derivative of the un- derlying marginal distributions. Furthermore, our framework allows for more complex arXiv:1805.08845v4 [stat.ML] 10 Jul 2021 outcomes such as images, sequences, and graphs. -
The Neyman-Rubin Model of Causal Inference and Estimation Via Matching Methods∗
The Neyman-Rubin Model of Causal Inference and Estimation via Matching Methods∗ Forthcoming in The Oxford Handbook of Political Methodology, Janet Box-Steffensmeier, Henry Brady, and David Collier, eds. Jasjeet S. Sekhon † 11/16/2007 (15:57) ∗I thank Henry Brady, Wendy Tam Cho, David Collier and Roc´ıo Titiunik for valuable comments on earlier drafts, and David Freedman, Walter R. Mebane, Jr., Donald Rubin and Jonathan N. Wand for many valuable discussions on these topics. All errors are my responsibility. †Associate Professor, Travers Department of Political Science, Survey Research Center, UC Berkeley. [email protected], HTTP://sekhon.berkeley.edu/, 510.642.9974. “Correlation does not imply causation” is one of the most repeated mantras in the social sciences, but its full implications are sobering and often ignored. The Neyman-Rubin model of causal inference helps to clarify some of the issues which arise. In this chapter, the model is briefly described, and some consequences of the model are outlined for both quantitative and qualitative research. The model has radical implications for work in the social sciences given current practices. Matching methods, which are usually motivated by the Neyman-Rubin model, are reviewed and their properties discussed. For example, applied researchers are often surprised to learn that even if the selection on observables assumption is satisfied, the commonly used matching methods will generally make even linear bias worse unless specific and often implausible assumptions are satisfied. Some of the intuition of matching methods, such as propensity score matching, should be familiar to social scientists because they share many features with Mill’s methods, or canons, of inference. -
Automating Path Analysis for Building Causal Models from Data
From: AAAI Technical Report WS-93-02. Compilation copyright © 1993, AAAI (www.aaai.org). All rights reserved. AutomatingPath Analysis for Building Causal Models from Data: First Results and Open Problems Paul R. Cohen Lisa BaUesteros AdamCarlson Robert St.Amant Experimental KnowledgeSystems Laboratory Department of Computer Science University of Massachusetts, Amherst [email protected]@cs.umass.edu [email protected] [email protected] Abstract mathematical basis than path analysis; they rely on evidence of nonindependence, a weaker criterion than Path analysis is a generalization of multiple linear regres- path analysis, which relies on evidence of correlation. sion that builds modelswith causal interpretations. It is Thosealgorithms will be discussed in a later section. an exploratory or discovery procedure for finding causal structure in correlational data. Recently, we have applied Wedeveloped the path analysis algorithm to help us path analysis to the problem of building models of AI discover causal explanations of how a complex AI programs, which are generally complex and poorly planning system works. The system, called Phoenix understood. For example, we built by hand a path- [Cohenet al., 89], simulates forest fires and the activities analytic causal model of the behavior of the Phoenix of agents such as bulldozers and helicopters. One agent, planner. Path analysis has a huge search space, however. called the fireboss, plans howthe others, whichare semi- If one measures N parameters of a system, then one can autonomous,should fight the fire; but things inevitably go build O(2N2) causal mbdels relating these parameters. wrong,winds shift, plans fail, bulldozers run out of gas, For this reason, we have developed an algorithm that and the fireboss soon has a crisis on its hands. -
Week 2: Causal Inference
Week 2: Causal Inference Marcelo Coca Perraillon University of Colorado Anschutz Medical Campus Health Services Research Methods I HSMP 7607 2020 These slides are part of a forthcoming book to be published by Cambridge University Press. For more information, go to perraillon.com/PLH. This material is copyrighted. Please see the entire copyright notice on the book's website. 1 Outline Correlation and causation Potential outcomes and counterfactuals Defining causal effects The fundamental problem of causal inference Solving the fundamental problem of causal inference: a) Randomization b) Statistical adjustment c) Other methods The ignorable treatment assignment assumption Stable Unit Treatment Value Assumption (SUTVA) Assignment mechanism 2 Big picture We are going to review the basic framework for understanding causal inference This is a fairly new area of research, although some of the statistical methods have been used for over a century The \new" part is the development of a mathematical notation and framework to understand and define causal effects This new framework has many advantages over the traditional way of understanding causality. For me, the biggest advantage is that we can talk about causal effects without having to use a specific statistical model (design versus estimation) In econometrics, the usual way of understanding causal inference is linked to the linear model (OLS, \general" linear model) { the zero conditional mean assumption in Wooldridge: whether the additive error term in the linear model, i , is correlated with the -
Causal Inference and Data Fusion in Econometrics∗
TECHNICAL REPORT R-51 First version: Dec, 2019 Last revision: March, 2021 Causal Inference and Data Fusion in Econometrics∗ Paul Hunermund¨ Elias Bareinboim Copenhagen Business School Columbia University [email protected] [email protected] Learning about cause and effect is arguably the main goal in applied economet- rics. In practice, the validity of these causal inferences is contingent on a number of critical assumptions regarding the type of data that has been collected and the substantive knowledge that is available about the phenomenon under investiga- tion. For instance, unobserved confounding factors threaten the internal validity of estimates, data availability is often limited to non-random, selection-biased sam- ples, causal effects need to be learned from surrogate experiments with imperfect compliance, and causal knowledge has to be extrapolated across structurally hetero- geneous populations. A powerful causal inference framework is required in order to tackle all of these challenges, which plague essentially any data analysis to varying degrees. Building on the structural approach to causality introduced by Haavelmo (1943) and the graph-theoretic framework proposed by Pearl (1995), the artificial intelligence (AI) literature has developed a wide array of techniques for causal learn- ing that allow to leverage information from various imperfect, heterogeneous, and biased data sources (Bareinboim and Pearl, 2016). In this paper, we discuss recent advances made in this literature that have the potential to contribute to econo- metric methodology along three broad dimensions. First, they provide a unified and comprehensive framework for causal inference, in which the above-mentioned problems can be addressed in full generality. -
Path Analysis in Mplus: a Tutorial Using a Conceptual Model of Psychological and Behavioral Antecedents of Bulimic Symptoms in Young Adults
¦ 2019 Vol. 15 no. 1 Path ANALYSIS IN Mplus: A TUTORIAL USING A CONCEPTUAL MODEL OF PSYCHOLOGICAL AND BEHAVIORAL ANTECEDENTS OF BULIMIC SYMPTOMS IN YOUNG ADULTS Kheana Barbeau a, B, KaYLA Boileau A, FATIMA Sarr A & KEVIN Smith A A School OF Psychology, University OF Ottawa AbstrACT ACTING Editor Path ANALYSIS IS A WIDELY USED MULTIVARIATE TECHNIQUE TO CONSTRUCT CONCEPTUAL MODELS OF psychological, cognitive, AND BEHAVIORAL phenomena. Although CAUSATION CANNOT BE INFERRED BY Roland PfiSTER (Uni- VERSIT¨AT Wurzburg)¨ USING THIS technique, RESEARCHERS UTILIZE PATH ANALYSIS TO PORTRAY POSSIBLE CAUSAL LINKAGES BETWEEN Reviewers OBSERVABLE CONSTRUCTS IN ORDER TO BETTER UNDERSTAND THE PROCESSES AND MECHANISMS BEHIND A GIVEN phenomenon. The OBJECTIVES OF THIS TUTORIAL ARE TO PROVIDE AN OVERVIEW OF PATH analysis, step-by- One ANONYMOUS re- VIEWER STEP INSTRUCTIONS FOR CONDUCTING PATH ANALYSIS IN Mplus, AND GUIDELINES AND TOOLS FOR RESEARCHERS TO CONSTRUCT AND EVALUATE PATH MODELS IN THEIR RESPECTIVE fiELDS OF STUDY. These OBJECTIVES WILL BE MET BY USING DATA TO GENERATE A CONCEPTUAL MODEL OF THE psychological, cognitive, AND BEHAVIORAL ANTECEDENTS OF BULIMIC SYMPTOMS IN A SAMPLE OF YOUNG adults. KEYWORDS TOOLS Path analysis; Tutorial; Eating Disorders. Mplus. B [email protected] KB: 0000-0001-5596-6214; KB: 0000-0002-1132-5789; FS:NA; KS:NA 10.20982/tqmp.15.1.p038 Introduction QUESTIONS AND IS COMMONLY EMPLOYED FOR GENERATING AND EVALUATING CAUSAL models. This TUTORIAL AIMS TO PROVIDE ba- Path ANALYSIS (also KNOWN AS CAUSAL modeling) IS A multi- SIC KNOWLEDGE IN EMPLOYING AND INTERPRETING PATH models, VARIATE STATISTICAL TECHNIQUE THAT IS OFTEN USED TO DETERMINE GUIDELINES FOR CREATING PATH models, AND UTILIZING Mplus TO IF A PARTICULAR A PRIORI CAUSAL MODEL fiTS A RESEARCHER’S DATA CONDUCT PATH analysis. -
To Adjust Or Not to Adjust? Sensitivity Analysis of M-Bias and Butterfly-Bias
To Adjust or Not to Adjust? Sensitivity Analysis of M-Bias and Butterfly-Bias The Harvard community has made this article openly available. Please share how this access benefits you. Your story matters Citation Ding, Peng, and Luke W. Miratrix. 2015. “To Adjust or Not to Adjust? Sensitivity Analysis of M-Bias and Butterfly-Bias.” Journal of Causal Inference 3 (1) (January 1). doi:10.1515/jci-2013-0021. Published Version 10.1515/jci-2013-0021 Citable link http://nrs.harvard.edu/urn-3:HUL.InstRepos:25207409 Terms of Use This article was downloaded from Harvard University’s DASH repository, and is made available under the terms and conditions applicable to Open Access Policy Articles, as set forth at http:// nrs.harvard.edu/urn-3:HUL.InstRepos:dash.current.terms-of- use#OAP Page 1 of 24 Journal of Causal Inference 1 2 3 4 5 6 7 Abstract 8 9 “M-Bias”, as it is called in the epidemiological literature, is the bias intro- 10 11 duced by conditioning on a pretreatment covariate due to a particular “M-Structure” 12 between two latent factors, an observed treatment, an outcome, and a “collider”. 13 This potential source of bias, which can occur even when the treatment and the out- 14 come are not confounded, has been a source of considerable controversy. We here 15 16 present formulae for identifying under which circumstances biases are inflated or 17 reduced. In particular, we show that the magnitude of M-Bias in Gaussian linear 18 structural equationFor models Review tends to be relatively Only small compared to confounding 19 bias, suggesting that it is generally not a serious concern in many applied settings. -
STATS 361: Causal Inference
STATS 361: Causal Inference Stefan Wager Stanford University Spring 2020 Contents 1 Randomized Controlled Trials 2 2 Unconfoundedness and the Propensity Score 9 3 Efficient Treatment Effect Estimation via Augmented IPW 18 4 Estimating Treatment Heterogeneity 27 5 Regression Discontinuity Designs 35 6 Finite Sample Inference in RDDs 43 7 Balancing Estimators 52 8 Methods for Panel Data 61 9 Instrumental Variables Regression 68 10 Local Average Treatment Effects 74 11 Policy Learning 83 12 Evaluating Dynamic Policies 91 13 Structural Equation Modeling 99 14 Adaptive Experiments 107 1 Lecture 1 Randomized Controlled Trials Randomized controlled trials (RCTs) form the foundation of statistical causal inference. When available, evidence drawn from RCTs is often considered gold statistical evidence; and even when RCTs cannot be run for ethical or practical reasons, the quality of observational studies is often assessed in terms of how well the observational study approximates an RCT. Today's lecture is about estimation of average treatment effects in RCTs in terms of the potential outcomes model, and discusses the role of regression adjustments for causal effect estimation. The average treatment effect is iden- tified entirely via randomization (or, by design of the experiment). Regression adjustments may be used to decrease variance, but regression modeling plays no role in defining the average treatment effect. The average treatment effect We define the causal effect of a treatment via potential outcomes. For a binary treatment w 2 f0; 1g, we define potential outcomes Yi(1) and Yi(0) corresponding to the outcome the i-th subject would have experienced had they respectively received the treatment or not.