What are the consequences of discretion when government shares the responsibility for regulatory compliance with the industry subject to regulation? Do differing underlying goals affect implementation? This article examines the implementation of Canada's Motor Vehicle Safety Act for fiscal years 1974–75 to 1981–82. Since the law creates opportunities for the exercise of discretion and those responsible for implementation (government versus industry) do not share the same underlying goals, one can expect that who implements the act will be of considerable importance. The data suggest that when incentives for compliance differ, discretion creates the opportunity for substantially different outcomes. Notable differences exist in the characteristics of recalls that manufacturers initiated and those that Transport Canada influen