Emilia Obińska-Wajda
pages: 78-85, JEL classification: B25, B52, D23, P14, Key words: Agency Theory, the New Insti tuti onal Economics, transacti on costs, property rights, Abstract: The aim of this arti cle is to show that the New Insti tuti onal Economics is an interdisciplinary stream combining economics, law, organizati on theory, politi cal sciences, sociology, and anthropology. The main theories which are part of the New Insti tuti onal Economics are: Agency Theory, Property Rights Theory and Transaction Costs Theory. The basic assumptions of these theories are mentioned in this paper. This article is an introduction to the New Institutional Economics and its main theories. For this purpose, it presents a brief guide for those who are interested in the New Institutional Economics. Finally, the article is accompanied by a short review of examples of empirical studies connected with these theories.