Divided Government and the Legislative Productivity of Congress, 1945-94

This paper contributes to the literature on divided government and legislative productivity. We begin by reexamining Mayhew's data on landmark enactments. We show that Mayhew's claim that divided government does not affect legislative productivity is a consequence of aggregating time series that exhibit different behavior. We then extend Mayhew's analysis by broadening the concept of significance and creating a new four-category measure that encompasses all 17,663 public laws enacted in the period of 1945-94. Using appropriate time-series techniques, we demonstrate that periods of divided government depress the production of landmark legislation by about 30%, at least when productivity is measured on the basis of contemporaneous perceptions of legislative significance. Divided government, however, has no substantive effect on the production of important, albeit not landmark, legislation and actually has a positive effect on the passage of trivial laws.