There have been a number of papers in the literature (pioneered by Sanjeev Goyal, Jackson, Kranton, amongst others) emphasising the role and importance of network structure in economics, the equilibrium arising therein and the relationship between the topology and other graph properties and the equilibrium.
Such networks arise in a number of cases, for example, research collaboration, social networks, crime networks, etc. My question is what published empirical studies have tested the hypothesis presented by the theory? Do such studies also find that the graph properties are critical, as predicted by the theory? Or is network effects in economics a theory-only area?