Greif specializes in the study of the social institutions that support economic development, and their history, incorporating game theory into his approach to this large subject.
[4]: 223-224 Among his research contributions is the view that during early stages of economic development, informal reputational mechanisms effectively substitute for formal contract enforcement regimes.
They provide the foundations of markets by efficiently assigning, protecting, and altering property rights; securing contracts; and motivating specialization and exchange.
Good institutions also encourage production by fostering saving, investment in human and physical capital, and development and adoption of useful knowledge.
They maintain a sustainable rate of population growth and foster welfare-enhancing peace; the joint mobilization of resources; and beneficial policies, such as the provision of public goods.