Walter R. Mebane

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W e show that the butterfly ballot used in Palm Beach County, Florida, in the 2000 presidential election caused more than 2,000 Democratic voters to vote by mistake for Reform candidate Pat Buchanan, a number larger than George W. Bush’s certified margin of victory in Florida. We use multiple methods and several kinds of data to rule out alternative(More)
We address a major discrepancy in matching methods for causal inference in observational data. Since these data are typically plentiful, the goal of matching is to reduce bias and only secondarily to keep variance low. However, most matching methods seem designed for the opposite problem, guaranteeing sample size ex ante but limiting bias by controlling for(More)
Genetic Optimization Using Derivatives We describe a new computer program that combines evolutionary algorithm methods with a derivative-based, quasi-Newton method to solve di cult unconstrained optimization problems. The program, called GENOUD (GENetic Optimization Using Derivatives), e ectively solves problems that are nonlinear or perhaps even(More)
The Wrong Man is President! Overvotes in the 2000 Presidential Election in Florida Using ballot-level data from the NORC Florida ballots project and ballot-image files, I argue that overvoted ballots in the 2000 presidential election in Florida included more than 50,000 votes that were intended to go to either Bush or Gore but instead were discarded. The(More)
Inspired by analyses of majoritarian systems, students of consensual polities have analyzed strategic voting due to barriers to party success, namely, district magnitude and threshold. Given the prevalence of coalition governments in proportional systems, we analyze a type of strategic voting seldom studied: how expected coalition composition affects voter(More)
Election Forensics: Vote Counts and Benford’s Law How can we be sure that the declared election winner actually got the most votes? Was the election stolen? This paper considers a statistical method based on the pattern of digits in vote counts (the second-digit Benford’s Law, or 2BL) that may be useful for detecting fraud or other anomalies. The method(More)
We propose applying the multiparametric spatiotemporal autoregressive (m-STAR) model as a simple approach to estimating jointly the pattern of connectivity and the strength of contagion by that pattern, including the case where connectivity is endogenous to the dependent variable (selection). We emphasize substantively-theoretically guided (i.e.,(More)
We propose a method for estimating the causal effect of a treatment, binary or continuous, on an outcome in the presence of a high-dimensional vector of confounders. Rather than estimate an intermediate quantity, like a propensity score or selection model, we fit a tensorspline regression model for the outcome and then directly estimate counterfactual(More)
Inferences about counterfactuals are essential for prediction, answering ‘‘what if ’’ questions, and estimating causal effects. However, when the counterfactuals posed are too far from the data at hand, conclusions drawn from well-specified statistical analyses become based on speculation and convenient but indefensible model assumptions rather than(More)