Essays on networks and information dynamics

The theory of networks has been growing at a very fast pace in the last 20 years, in terms of scholars working in the field, of the quality and complexity of theoretical instruments adopted, and of the availability of empirical data. The first three chapters of this dissertation explore different areas in which networks are being used as fundamental tools to study information dynamics and their economic relevance. In "Citations are Forever: Modeling Constrained Network Formation", I consider a model of constrained network formation, and employ it to identify a lower bound to the relevance of environmental factors on citation flows to scientific articles. In "Opinion Dynamics in Social Networks: Theory and Experimental Evidence" (joint work with Luca Stanca), we consider a new model of opinion formation over a social network, and test it in an experimental setting. In "Not that Fundamental: Bubbles and Financial Networks", I highlight the possibility of rational asset price bubbles in financial markets with finite number of agents and amount of wealth, and sketch some consequences for systemic risk, in light of the results of recently proposed models of financial networks. In "The Impact of Peer Pressure on Tax Compliance: a Field Experiment" (joint work with Simona Gamba), the social network in which agents move is only implicit, but the information flow is clear: the experimental design allows us to manipulate the sellers' perception about social norms on tax compliance, and to identify an effect on their own propensity towards compliance.