Selectorate theory

The selectorate theory is detailed in The Logic of Political Survival, authored by Bruce Bueno de Mesquita of New York University (NYU), Alastair Smith of NYU, Randolph M. Siverson of UC Davis, James D. Morrow of the University of Michigan.

The theory operates on two fundamental groups, the Winning Coalition and the Selectorate, both drawn from the overall populace in a state. The Winning Coalition is a subset of the Selectorate, and the Selectorate is a subset of the overall population. The Selectorate is simply those within the state that have a say in policy outcome (in the United States, for example, it would be all citizens over the age of 18 eligible to vote). The Winning Coalition is a proportion of the Selectorate sufficient to choose and sustain a leader in office.

Distribution of goods

A public good is such a good that everyone non-exclusively enjoys, such as national defense. The public good in this example would be the security provided to citizens of a state. A private good is a good that is enjoyed exclusively by a select few (usually within the Winning Coalition) and cannot be shared. An example of such a good would be anything exclusionary, such as food surpluses.

It can be said, then, that everyone in the Selectorate (including the Winning Coalition) reap the benefits of public goods while only those within the Winning Coalition enjoy private goods.

Government types, leaders, and challenger threats

According to the selectorate theory, a leader has the greatest chance of political survival when the Selectorate is large and the Winning Coalition is small (an autocracy). This is because those who are in a winning coalition can easily be replaced by other members of the selectorate who are not in the Winning Coalition. Thus, the costs of defection for those members of the Winning Coalition can be potentially large—namely the loss of all private goods. Similarly, the chances of a challenger in replacing the leader are similarly smallest in such an autocratic system since those in the winning coalition would be hard pressed to defect. Private goods are highest in such a system vis-à-vis public goods.

In a monarchy, where the Selectorate is small and the Winning Coalition is even smaller, provides the challenger with a greater opportunity to overthrow the current leader. This is because the proportion of Selectorate members who are also in the Winning Coalition is relatively large. That is to say if a new leader comes to power, chances are a given member of the Winning Coalition will remain within the coalition. The incentive for defection in order to attain a greater amount of goods offered by a challenger is not, in this case, outweighed by the risk of not being included in the new Winning Coalition. Here, the proportion of private goods in relation to public goods is seen declining.

A scenario where both the Winning Coalition is large and the Selectorate is even larger provides the least amount of stability to a leader’s occupancy of power (such a system is a Democracy). Here, the proportion of public goods outweigh private goods simply because of the sheer size of the Winning Coalition; it would be far too costly to provide private goods to every individual member of the Winning Coalition when the benefits of public goods would be enjoyed by all. Because of this fact—that the leader cannot convince Winning Coalition members to remain loyal through private good incentives (which are in turn cost-restrictive)—the challenger poses the greatest threat to the incumbent. Furthermore, this degree of loyalty to the incumbent leader—whatever the government structure may be—is called the Loyalty Norm.

A scenario where the Winning Coalition is large and the Selectorate is small is theoretically impossible since the Winning Coalition is a subset of the Selectorate.