Findings from a study that explored the motivations of legislators to oversee and control program implementation are presented in this paper. Implementation is viewed as a contract between the legislative and executive branches with legislators acting as monitors who use oversight to control the agencies contracted to implement policy. A total of 57 elite interviews with legislators, committee staff, and legislative agency staff were conducted in 6 states--Arizona, California, Florida, Georgia, Minnesota, and Pennsylvania--to examine the constraints of legislative monitoring, the resources for legislative control of implementing agencies, and the extent to which legislatures use available resources to oversee implementation contracts. Principal-agent theory suggests that in all contractual relationships information is distributed unevenly among the contracting parties, skewed in favor of the agent. Data from the states illustrate how legislatures drew on their institutional and political resources to enhance their access to information and their control over contract implementation. Three tables are included. (27 references) (LMI)