Policy Inertia, Election Uncertainty, and Incumbency Disadvantage of Political Parties
研究发现美国战后选举中执政党存在“在位劣势”，即长期执政后支持率下降，并证明政策惯性与选举结果不确定性可解释这一现象。
Abstract We document that postwar U.S. elections show a strong pattern of “incumbency disadvantage”: if a party has held the presidency of the country or the governorship of a state for some time, that party tends to lose popularity in the subsequent election. We show that this fact can be explained by a combination of policy inertia and unpredictability in election outcomes. A quantitative analysis shows that the observed magnitude of incumbency disadvantage can arise in several different models of policy inertia. Normative and positive implications of policy inertia leading to incumbency disadvantage are explored.