Models of direct-interactions-driven collective economic phenomena

The present thesis consists of seven papers specifying and analysing models of direct-interactions-driven collective economic phenomena. Within theories and models of coordination in large decentralized market economies (and analogously also within theories and models of coordination in natural systems, for instance models of magnetism) the notion of direct interactions is to be contrasted with the notion of indirect interaction via aggregate signals, such as the price system. The presented papers apply a direct-interactions-based modelling to the analysis of economic phenomena, such as the emergence of collective economic sentiment, business cycles, and new-product diffusion.