Ethnic networks are a way of overcoming informal barriers to trade such as information costs, risk, and uncertainty by building trust and by substituting for the difficulty of enforcing contracts internationally. We study networks which emerge from the interaction (i) between migrants and...

We develop a model where the unemployed workers in the city can find a job either directly or through weak or strong ties. We show that, in denser areas, individuals choose to interact with more people and meet more random encounters (weak ties) than in sparsely populated areas. We also...