The aim of this presentation is the following:
During these last thirty years, revival in institutional economic study can be opposed to “old” institutionalism. Giving up strong holism in which institutions entirely constraint individual behaviors, “new” institutionalism asks us to resolve the question of respective part of individuals, organizations and institutions in economic phenomena.

There is no consensus in new institutional approaches about the explanation of the respective role of human actor and institution. Moreover, there is no consensus on this point inside a same paradigm. For example, see the opposition between Hodgson and Darwinist evolution on the one side and Nelson, Winter, Dosi and Lamarckian evolution on the other side. See also, in NIE, the difference between, on the one hand, North and necessity to understand how ideologies – shared believes in non-ergodic world –come from cognitive limitation of individuals and, on the other hand, Greif or Ménard and their focus on institutions.

Analyzing this problem implies understanding individual intentionality.
At least three empirical stakes arise from intentionality:
- 1) The nature of rationality. What kind of behavioral hypothesis are necessary? Is it sufficient to take in account only opportunistic behaviors? Is it sufficient to take in account only “rational” action? Do ideologies matter?
- 2) The interaction between individual and institution. Is it possible to believe that institutions be the result of rational agents’ interaction? Is Pareto optimal Nash equilibrium always possible? How is possible to give rise to new institutions? How is it possible to combine institutional regularity with individual freedom?
- 3) The interaction between collective agent and individual agent. How can organization be a collective player in which individual aims aren’t the same as organizational aim? Is Nelson & Winter’s “truce” assumption necessary?

My underlying point of view is the following. More often that not reflections on these subjects bump against a pitfall: the impossibility to escape analysis in which intentionality is dissolved in psychological or social deterministic laws. Warding off this pitfall presupposes to award capacity of self-referentiality to individual agent.