The definition and measurement of the impact of laws and courts is a subject of disagreement and uncertainties. In this article, law is understood as a public, general, and binding command enforceable through state coercion. Assessments on the effects of laws on democracy and development focus on changes in specific social indicators. The evaluation of impact relates to the availability and reliability of judicial statistics and the impact of laws depends on political and social conditions. The interaction of laws can (...) be studied in three contextual variables: the structure and competitiveness of political systems, the structure and performance of the judiciary, and the organizational endowments of the social or political actors, such as social and labor movements that use the law. This interaction shows how and why certain conditions affect impact. It also speculates, about some additional developments that might follow from the relationships between law and these three variables. (shrink)