Voting games with incomplete information

voting;Social Sciences

Patty, John Wiggs ; Palfrey, Thomas R.

University:California Institute of Technology

Department:Humanities and Social Sciences

关键词: voting;    Social Sciences;   

Others  :  https://thesis.library.caltech.edu/8162/2/Patty%202001.pdf

美国|英语

来源: Caltech THESIS

【 摘 要 】

We examine voting situations in which individuals have incomplete information overeach others' true preferences. In many respects, this work is motivated by a desire toprovide a more complete understanding of so-called probabilistic voting.

Chapter 2 examines the similarities and differences between the incentives facedby politicians who seek to maximize expected vote share, expected plurality, or probabilityof victory in single member: single vote, simple plurality electoral systems.We find that, in general, the candidates' optimal policies in such an electoral systemvary greatly depending on their objective function. We provide several examples, aswell as a genericity result which states that almost all such electoral systems (withrespect to the distributions of voter behavior) will exhibit different incentives for candidateswho seek to maximize expected vote share and those who seek to maximizeprobability of victory.

In Chapter 3, we adopt a random utility maximizing framework in which individuals'preferences are subject to action-specific exogenous shocks. We show thatNash equilibria exist in voting games possessing such an information structure and inwhich voters and candidates are each aware that every voter's preferences are subjectto such shocks. A special case of our framework is that in which voters are playinga Quantal Response Equilibrium (McKelvey and Palfrey (1995), (1998)). We thenexamine candidate competition in such games and show that, for sufficiently largeelectorates, regardless of the dimensionality of the policy space or the number of candidates,there exists a strict equilibrium at the social welfare optimum (i.e., the pointwhich maximizes the sum of voters' utility functions). In two candidate contests wefind that this equilibrium is unique.

Finally, in Chapter 4, we attempt the first steps towards a theory of equilibrium ingames possessing both continuous action spaces and action-specific preference shocks.Our notion of equilibrium, Variational Response Equilibrium, is shown to exist in allgames with continuous payoff functions. We discuss the similarities and differencesbetween this notion of equilibrium and the notion of Quantal Response Equilibriumand offer possible extensions of our framework.