Predicting Politics

Bruce Mesquita

The model itself depicts a game in which actors simultaneously make proposals and exert influence on one another. They then evaluate options and build coalitions by shifting positions on the issue in question. The above steps are repeated sequentially until the issue is resolved... Resolution or breakdown occurs when the costs of continued negotiation are estimated to exceed the expected benefits from such continued discussions.

The model assumes that each player has the same time discount rate. When the shift in the median voter position (or position based on some other pertinent decision rule) predicted from one round to the next is small enough, given the time discount rate, then the model assumes bargaining ends. The outcome predicted at this point depends upon the decision rule in force. If majority rule (or some supermajority rule) is in force, then the policy outcome that corresponds with the rule (e.g., the median voter's policy position at the end of bargaining if majority rule is in force) is the predicted outcome...

In the game, each player knows three factors: the potential power and stated or inferred policy position of each actor on each issue examined, and the salience each actor associates with those issues. The decision makers, stakeholders, or players do not know how much others value alternative outcomes or what perceptions others have about their risks and opportunities. Each decision maker chooses based on his or her perceptions and expectations, with these perceptions and expectations about the play of others and the general situation sometimes being in error.

Strategies in the game consist of sequences of policy proposals (including no proposal) from each player to each other player.. In the model discussed here, .. players are interested in maximizing their welfare on [policy].

Decision makers care about the policy choice on the issue continuum and so, from that perspective, are reluctant to move from the position with which they have associated themselves to a position on the opposite side of the median voter. However, they also are interested in enhancing their personal welfare by being seen as instrumental in helping to form a winning coalition. Naturally, the location of the winning coalition may not be constrained to fall on the same side of the issue continuum (relative to the median voter's position) as their own stated negotiating stance. If a player values credit for helping to forge a winning coalition sufficiently, then the player will be prepared to shift positions, even moving to the opposite side of the policy space provided doing so supplies sufficient utility regarding credit for helping to "make a deal." Such a player can be attracted to a new position without being coerced. Such a player may strike a policy compromise with others in order to gain credit as the broker of an agreement.