The article proposes and develops a concept - social productivity - to complement the widely used concepts of social capital and economic productivity. All three concepts are concerned with structured groups, which include organizations, institutions, and societies. However, while social capital focuses on a group's social resources and economic productivity focuses on a group's economically relevant goods and services, social productivity focuses on a group's social outputs. Four social outputs of groups are identified: (1) standards for behavior, (2) reputation, (3) symbols, and (4) trust and perceptions of fairness. These social outputs are important to a group not only because they affect the degree of commitment to the group by its participants but also because they affect the responses to the group by others. From the perspective of social productivity, government adopts law (formal standards for behavior) in order to preserve the reputation of important groups, provide symbols, and maintain or increase trust and fairness. To illustrate the concept of social productivity, the article examines ways that federal law on investment companies and investment advisers deals with conflicts of interest.