Monday, April 23, 2012

Katie Baldiga defends her Ph.D. dissertation

Defense 1 (Offense 0)

Katie Baldiga and her committee of admirers: Iris Bohnet, Al Roth, Jerry Green (and Drew Fudenberg via skype)
(Alternative caption: Katie B. got her Ph.D.)

The three papers in Katie's dissertation are so wide ranging that she characterizes them together as "Essays in Microeconomics." (I blogged about her experimental paper here.)

A Failure of Representative Democracy (Job Market Paper 1) 
In this paper, we study representative democracy, one of the most popular classes of collective decision-making mechanisms, and contrast it with direct democracy. In a direct democracy, individuals have the opportunity to vote over the alternatives in every choice problem the population faces. In a representative democracy, the population commits to a candidate ex ante who will then make choices on its behalf. While direct democracy is normatively appealing, representative democracy is the far more common institution because of its practical advantages. The key question, then, is whether representative democracy succeeds in implementing the choices that the group would make under direct democracy. We find that, in general, it does not. We analyze the theoretical setting in which the two methods are most likely to lead to the same choices, minimizing potential sources of distortion. We model a population as a distribution of voters with strict preferences over a finite set of alternatives and a candidate as an ordering of those alternatives that serves as a binding, contingent plan of action. We focus on the case where the direct democracy choices of the population are consistent with an ordering of the alternatives. We show that even in this case, where the normative recommendation of direct democracy is clear, representative democracy may not elect the candidate with this ordering.
Gender Differences in Willingness to Guess and the Implications for Test Scores (Job Market Paper 2) 
Multiple-choice tests play a large role in determining academic and professional outcomes. Performance on these tests hinges not only on a test-taker's knowledge of the material but also on his willingness to guess when unsure about the answer. In this paper, we present the results of an experiment that explores whether women skip more questions than men. The experimental test consists of practice questions from the World History and U.S. History SAT II subject tests; we vary the size of the penalty imposed for a wrong answer and the salience of the evaluative nature of the task. We find that when no penalty is assessed for a wrong answer, all test-takers answer every question. But, when there is a small penalty for wrong answers and the task is explicitly framed as an SAT, women answer significantly fewer questions than men. We see no differences in knowledge of the material or confidence in these test-takers, and differences in risk preferences fail to explain all of the observed gap. Because the gender gap exists only when the task is framed as an SAT, we argue that differences in competitive attitudes may drive the gender differences we observe. Finally, we show that, conditional on their knowledge of the material, test-takers who skip questions do significantly worse on our experimental test, putting women and more risk averse test-takers at a disadvantage.
Assent-Maximizing Social Choice with Jerry R. Green, forthcoming in Social Choice and Welfare
We take a decision theoretic approach to the classic social choice problem, using data on the frequency of choice problems to compute social choice functions. We define a family of social choice rules that depend on the population's preferences and on the probability distribution over the sets of feasible alternatives that the society will face. Our methods generalize the well-known Kemeny Rule. In the Kemeny Rule it is known a priori that the subset of feasible alternatives will be a pair. We define a distinct social choice function for each distribution over the feasible subsets. Our rules can be interpreted as distance minimization -- selecting the order closest to the population's preferences, using a metric on the orders that reflects the distribution over the possible feasible sets. The distance is the probability that two orders will disagree about the optimal choice from a randomly selected available set. We provide an algorithmic method to compute these metrics in the case where the probability of a given feasible set is a function only of its cardinality.

Katie is one of the group of job market candidates I blogged about here: Five Harvard candidates for the Economics job market this year (2011-12).

She and her significant other LC solved the two-body problem this year (!), and will be together at The Ohio State University, which is now more than ever a hotbed of experimental economics.

Three more defenses are coming up this week.

Welcome to the club, Katie.

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