New Institutional Economics (NIE) is an economic perspective that attempts to extend economics by focusing on the institutions (that is to say the social and legal norms and rules) that underlie economic activity and with analysis beyond earlier institutional economics and neoclassical economics.
The NIE assume that individuals are rational and that they seek to maximize their preferences, but that they also have cognitive limitations, lack complete information and have difficulties monitoring and enforcing agreements. As a result, institutions form in large part as an effective way to deal with transaction costs.