This article discusses definitions of institutions and their terminological ambivalence. Such an ambivalence is the result of a lack of interest for the structural characteristics of institutions. This does not allow researchers to use the methodological potential of institutional approach adequately. To determine the behavioral features that characterize institutions as social artifacts, the article discusses their main social properties: regularity, alternatives, anonymity, importance, observability, reflexivity, effectiveness, arbitrage relations, internalization, cost-dependence, and action-dependence. The author emphasizes that institutional theories should analyze not only the processes of development or formation of institutions, but also their structural features. The article concludes that the study of social characteristics of the institutions is necessary to improve the quality of economic policy: only by understanding the limitations under which institutions are implemented in social space, one can offer policy measures that are able to transform people’s behavior.