Fallback Bargaining

Fallback bargaining is a bargaining procedure under which bargainers begin by indicating their preference rankings over all alternatives. They then fall back, in lockstep, to less and less preferred alternatives - starting with first choices, then adding second choices, and so on - until an alternative is found on which all bargainers agree. This common agreement, which becomes the outcome of the procedure, may be different if a decision rule other than unanimity is used.BARGAINING ; SOCIAL CHOICE ; NASH EQUILIBRIUM

Dividing the Indivisible: Procedures for Allocating Cabinet Ministries to Political Parties in a Parliamentary System

Political parties in Northern Ireland recently used a divisor method of apportionment to choose, in sequence, ten cabinet ministries. If the parties have complete information about each others' preferences, we show that it may not be rational for them to act sincerely by choosing their most-preferred ministry that is available. One consequence of acting sophisticatedly is that the resulting allocation may not be Pareto-optimal, making all the parties worse off. Another is nonmonotonicty-choosing earlier may hurt rather than help a party. We introduce a mechanism that combines sequential choices with a structured form of trading that results in sincere choices for two parties. Although there are difficulties in extending this mechanism to more than two parties, other approaches are explored, such as permitting parties to making consecutive choices not prescribed by an apportionment method. But certain problems, such as eliminating envy, remain.APPORTIONMENT METHODS; CABINETS; SEQUENTIAL ALLOCATION; MECHANISM DESIGN; FAIRNESS

Resolving Social Issues in a Merger: A Fair-Division Approach

One of the most elusive ingredients in the success of a deal is what deal makers euphemistically refer to as "Social issues" - how power, position, and status will be allocated among the merging companies' executives. A failure to resolve these issues often leads to the destruction of shareholder wealth and portrayal of top executives as petty corporates chieftains, unable to subordinate their selfish interests to the goal of promoting shareholder well-being.MERGERS ; EFFICIENCY ; EQUITY

Voter Sovereignty and Election Outcomes

APPROVAL VOTING; ELECTIONS; CONDORCET WINNER/LOSER; NASH EQUILIBRIUM.

Going from Theory to Practice: The Mixed Success of Approval Voting

Approval voting (AV) is a voting system in which voters can vote for, or approve of, as many candidates as they like in multicandidate elections. In 1987 and 1988, four scientific and engineering societies, collectively comprising several hundred thousand members, used AV for the first time. Since then, about half a dozen other societies have adopted AV. Usually its adoption was seriously debated, but other times pragmatic or political considerations proved decisive in its selection. While AV has an ancient pedigree, its recent history is the focus of this paper. Ballot data from some of the societies that adopted AV are used to compare theoretical results with experience, including the nature of voting under AV and the kinds of candidates that are elected. Although the use of AV is generally considered to have been successful in the societies-living up to the rhetoric of its proponents-AV has been a controversial reform. AV is not currently used in any public elections, despite efforts to institute it, so its success should be judged as mixed. The chief reason for its nonadoption in public elections, and by some societies, seems to be a lack of key "insider" support.APPROVAL VOTING; ELECTIONS; PROFESSIONAL SOCIETIES; CONDORCET CANDIDATE.

PTAS for Minimax Approval Voting

We consider Approval Voting systems where each voter decides on a subset to candidates he/she approves. We focus on the optimization problem of finding the committee of fixed size k minimizing the maximal Hamming distance from a vote. In this paper we give a PTAS for this problem and hence resolve the open question raised by Carragianis et al. [AAAI'10]. The result is obtained by adapting the techniques developed by Li et al. [JACM'02] originally used for the less constrained Closest String problem. The technique relies on extracting information and structural properties of constant size subsets of votes.Comment: 15 pages, 1 figur

To Mobilize of Not to Mobilize: Catch 22s in International Crises

IN his classic novel, "Catch-22" (1961), Joseph Heller describes a thoroughly frustrating situation faced by a combat pilot in World War II. This is generalized to a "generic" 2x2 strict ordinal game, in which whatever strategy the column player chooses, the best response of the row player is to inflict on the column player a worst or next-worst outcome, and possibly vice-versa. The 12 specific games subsumed by the generic game are called catch-22 games.GAMES

The Paradox of Disconnected Coalitions

COALITION FORMATION; DYNAMIC ANALYSIS; SINGLE-PEAKEDNESS; LEGISLATURES; MILITARY ALLIANCES.

Game Theory and Emotions

Game theory

Two Stage Auctions II: Common-Value Strategies and the Winner's Curse

game theory ; supply ; economic models ; economic equilibrium