Presidential and Congressional Vote-Share Equations

Three vote-share equations are estimated and analyzed in this article, one for presidential elections, one for on-term House elections, and one for midterm House elections. The sample period is 1916–2006. Considering the three equations together allows one to test whether the same economic variables affect each and to examine various serial correlation and coattail possibilities. The main conclusions are (1) there is strong evidence that the economy affects all three vote shares and in remarkably similar ways; (2) there is no evidence of any presidential coattail effects on the on-term House elections; (3) there is positive serial correlation in the House vote, which likely reflects a positive incumbency effect for elected representatives; and (4) the presidential vote share has a negative effect on the next midterm House vote share, which is likely explained by a balance argument.