Several studies of the post-war American political economy find that Democratic presidents have been more successful than Republicans. Most recently, Bartels (2008) found that economic growth had been greater and that unemployment and income inequality had been lower under Democratic presidents since 1948. If true, these findings combined with the frequent success of Republicans in presidential elections pose a challenge to theories of retrospective voting and responsible party government. This reexamination of these findings indicates that they are an artifact of specification error. Previous estimates did not properly take into account the lagged effects of the economy. Once lagged economic effects are taken into account, party differences in economic performance are shown to be the effects of economic conditions inherited from the previous president and not the consequence of real policy differences. Specifically, the economy was in recession when Republican presidents became responsible for the economy in each of the four post-1948 transitions from Democratic to Republican presidents. This was not the case for the transitions from Republicans to Democrats. When economic conditions leading into a year are taken into account, there are no presidential party differences with respect to growth, unemployment, or income inequality.