THE COST OF RULING: AN EXPLORATION IN U.S. GUBERNATORIAL ELECTIONS

The cost of ruling is a well-established inductive law in political science. In the developed democracies, incumbent parties incur a penalty of 2 to 3 percentage points per term, on average. We argue that this estimate obscures the fact that the share of the vote going to the incumbents does not decrease the longer they stay in office. Rather, as long as they are re-elected, incumbents win about the same share of the vote. This stays relatively constant until they are defeated, at which time the loss averages 12 percentage points independent of the number of terms the party has been in control.