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Voting Games with Incomplete Information


Patty, John Wiggs (2001) Voting Games with Incomplete Information. Dissertation (Ph.D.), California Institute of Technology. doi:10.7907/0ebb-vz47.


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

Chapter 2 examines the similarities and differences between the incentives faced by politicians who seek to maximize expected vote share, expected plurality, or probability of victory in single member: single vote, simple plurality electoral systems. We find that, in general, the candidates' optimal policies in such an electoral system vary greatly depending on their objective function. We provide several examples, as well as a genericity result which states that almost all such electoral systems (with respect to the distributions of voter behavior) will exhibit different incentives for candidates who seek to maximize expected vote share and those who seek to maximize probability 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 that Nash equilibria exist in voting games possessing such an information structure and in which voters and candidates are each aware that every voter's preferences are subject to such shocks. A special case of our framework is that in which voters are playing a Quantal Response Equilibrium (McKelvey and Palfrey (1995), (1998)). We then examine candidate competition in such games and show that, for sufficiently large electorates, 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 point which maximizes the sum of voters' utility functions). In two candidate contests we find that this equilibrium is unique.

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

Item Type:Thesis (Dissertation (Ph.D.))
Subject Keywords:voting ; Social Sciences
Degree Grantor:California Institute of Technology
Division:Humanities and Social Sciences
Major Option:Social Science
Thesis Availability:Public (worldwide access)
Research Advisor(s):
  • Palfrey, Thomas R.
Thesis Committee:
  • Palfrey, Thomas R. (chair)
  • Banks, Jeffrey S. (co-chair)
  • Border, Kim C.
  • McKelvey, Richard D.
Defense Date:23 April 2001
Record Number:CaltechTHESIS:03242014-155640911
Persistent URL:
Patty, John Wiggs0000-0002-1142-9334
Default Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:8162
Deposited On:25 Mar 2014 16:31
Last Modified:29 Nov 2022 21:56

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