ABSTRACT
This chapter explains the most important infrastructures in society are interaction regularities or patterns in human exchanges. These interaction-based institutions correspond to the organizing processes of a society, and research focusing on the economics of organization usually only addresses part of this more fundamental issue. One weakness in applying the idea of human interactions and exchanges as something based on contractual relations is the distinct, well-established meaning of the term contract in jurisprudence, which differs from the way the term often is used in economic analysis. Institutions function like 'rationality contexts', which emerge in human interactions. Although institutions are mechanisms for the reduction of uncertainty, in their emergent forms they simultaneously reproduce (new) uncertainty. The infrastructures of human interaction absorb crucial uncertainties, and hence they reduce the demands on the cognitive capacity of the human mind. Three fundamental rationalities underlying human interactions are suggested, founded on, respectively, calculative, idealistic, and genuine relationships.
