of the Economic Opportunity Act of 1964. My thanks to Yeheske1 Hasenfe1d, Rosemary Sarri, and Joseph Sanders for comments on an early draft.. DABSTRACT An important question to both social theory and policy is the impact of law on behavior. This question has received considerable empirical attention, but the need for a consistent theoretical approach is evident. In this paper a preliminary theory of legal impact is suggested, and one specific aspect of it is detailed. The paper points out that a number of distinctions are necessary in a the~ry of impact. First, impact may occur at two level~, thc:).t of compliance and that of broader social impact. Second, three factors may be expected to influence impact, the source of the law, the content...