When Voters Strategize, Approval Voting Elects Condorcet Winners but Condorcet Methods can Elect Condorcet Losers

نویسنده

  • Warren Schudy
چکیده

We show that approval voting strategic equilibria are closely related to honest Condorcet Winners. There exists an approval equilibrium with a clear font-runner F and runner-up R if and only if the F is the clear Condorcet Winner and R the Condorcet runner-up. In contrast, we show that margins-based Condorcet methods can elect a Condorcet Loser with non-zero probibility when voters vote tactically. With strategic agents, approval voting is better at electing Condorcet Winners than some Condorcet methods! It turns out these ideas were previously discovered by J.F. Laslier [6] and Burt Monroe [7].

برای دانلود رایگان متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید

ثبت نام

اگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید

منابع مشابه

Critical Strategies Under Approval Voting: Who Gets Ruled In And Ruled Out

We introduce the notion of a “critical strategy profile” under approval voting (AV), which facilitates the identification of all possible outcomes that can occur under AV. Included among AV outcomes are those given by scoring rules, single transferable vote, the majoritarian compromise, Condorcet systems, and others as well. Under each of these systems, a Condorcet winner may be upset through m...

متن کامل

Approval voting in subset elections

Approval voting is designed to be "insensitive to numbers" of voters, and likely to elect a Condorcet candidate. However, the result of an election among one group of candidates gives no information about the results of elections among any other groups, even if every voter follows the recommended utilitymaximizing strategy, which places strong restrictions on the individual voter's subset ballo...

متن کامل

Condorcet efficiency: A preference for indifference

The Condorcet winner in an election is the candidate who would be able to defeat all other candidates in a series of pairwise elections. The Condorcet efficiency of a voting procedure is the conditional probability that it will elect the Condorcet winner, given that a Condorcet winner exists. The study considers the Condorcet efficiency of weighted scoring rules (WSR’s) on three candidates for ...

متن کامل

Voting Systems that Combine Approval and Preference

Information on the rankings and information on the approval of candidates in an election, though related, are fundamentally different—one cannot be derived from the other. Both kinds of information are important in the determination of social choices. We propose a way of combining them in two hybrid voting systems, preference approval voting (PAV) and fallback voting (FV), that satisfy several ...

متن کامل

A note on Approval Voting and electing the Condorcet loser

Analytical representations are developed for the probability that Approval Voting (AV) elects the Condorcet Loser in three-alternative elections with large electorates. A comparison of AV is then made to Plurality Rule (PR) to show that AV is much less susceptible to the risk of electing the Condorcet loser than PR. All calculations in this analysis are based on IAC-like assumptions.

متن کامل

ذخیره در منابع من


  با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید

عنوان ژورنال:

دوره   شماره 

صفحات  -

تاریخ انتشار 2007