“Diversity in Committees“, with Zia-Ul-Hassan Khan and Friederike Mengel
Abstract Committee members belong to one of two groups which may differ along two dimensions: preferences and information structures. They receive private information on a state of the world, deliberate and vote. Different information structures aid information aggregation by reducing correlation between signals, while different preferences harm it by stifling communication. When both dimensions vary, welfare is either increasing, decreasing or non-monotonic in committee diversity. This depends on model parameters and whether agents are Bayesian or neglect correlation. We test model predictions in a laboratory experiment. Empirically, the positive impact of informational diversity broadly outweighs the negative impact of preference diversity.
“Strategic Voting in Two-Party Legislative Elections“, Revise & Resubmit at American Economic Review
Abstract It is commonly thought that in an election with two parties there can be no strategic voting – voters simply vote for their preferred candidate. In this paper, I show that strategic voting comes to the fore in legislative elections with multiple policy dimensions. In sharp contrast to single-district elections, the intensity of a voter’s preference on each dimension is irrelevant for her voting decision. Instead, she votes solely based on the dimension which is most likely to be pivotal in the legislature. Anticipating this behaviour, candidates put forward a different set of policies than they would in a single-district election. For large elections I show that the implemented policy bundle: (a) is uniquely pinned down by voter preferences, (b) is preferred by a majority of districts on each dimension, (c) is a Condorcet winner, if one exists. These properties are not guaranteed in a single-district election. Furthermore, I show that (i) parliamentary systems generate superior policies to presidential systems and (ii) voter polarisation affects outcomes in single-district elections but not legislative elections.
“How Transparency Kills Information Aggregation: Theory & Experiment”, with Sebastian Fehrler (American Economic Journal: Microeconomics, 2018) (Online Appendix)
Abstract We investigate the potential of transparency to influence committee decision-making. We present a model in which career concerned committee members receive private information of different type-dependent accuracy, deliberate and vote. We study three levels of transparency under which career concerns are predicted to affect behavior differently and test the model’s key predictions in a laboratory experiment. The model’s predictions are largely borne out – transparency negatively affects information aggregation at the deliberation and voting stages, leading to sharply different committee error rates than under secrecy. This occurs despite subjects revealing more information under transparency than theory predicts.
“Voting in Legislative Elections under Plurality Rule”, (Journal of Economic Theory, 2016)
Abstract Models of single district plurality elections show that with three parties anything can happen – extreme policies can win regardless of voter preferences. I show that when single district elections are used to fill a legislature, we get back to a world where the median voter matters. An extreme policy will generally only come about if it is preferred to a more moderate policy by the median voter in a majority of districts. The mere existence of a centrist party can lead to moderate outcomes even if the party itself wins few seats. I also show that, while some voters in a district will not vote for their nationally preferred party, in many equilibria they will want the candidate for whom they vote to win that district. This is never the case in single district elections. There, some voters always want the candidate they voted for to lose.
Abstract In existing legislative bargaining models the precise division of seats between parties has no bearing on some of: which coalition forms, which policy is adopted, how perks are divided – or even all three. These models also predict that the proposer should reap significantly larger rewards than the other players. Such predictions are at odds with longstanding empirics: government portfolios are generally allocated in proportion to seat share, and there is no proposer advantage. In this paper, I show that when each member of a party faces the electoral consequences of being in government, then seat shares matter a great deal: (1) For a given ranking of parties, changing their respective seat shares can bring about almost any coalition; (2) the implemented policy is a function of the coalition parties seat shares; (3) an increase in one coalition party’s seats will move the policy towards their preferred point but may increase or decrease their share of government perks. Furthermore, I show that (4) there can be equilibria in which the largest party is not in government, and (5) in many cases the larger coalition member will have all of its rent extracted by the junior member.