Legislative responses to shared executive authority: How the prospects for executive branch coordination affect congressional budgetary authority under separated powers

How do the prospects for executive branch coordination affect legislatures' willingness to expand or contract budgets for public agencies? A theory is advanced stating the conditions whereby Congress expands and contracts the budgets of U.S. federal executive agencies based upon the type of presidential loyalty displayed by agency heads, as well as whether Congress's policy interests are aligned with or opposed by presidents. One aspect of the theory posits that executive agencies' budgets exhibit relatively lower volatility in response to unreliable executive agency heads when Congress is controlled by a different party than the president compared to instances of unified party government. The evidence offers compelling, albeit mixed, support for the theory's testable predictions while gleaning novel empirical insights for understanding how the prospects for executive branch coordination via leadership appointees affect the contingent nature of Congress's decisions in shaping the funding of U.S. federal executive agencies.