We review the accumulated knowledge on city size distributions and determinants of urban growth. This topic is of interest because of a number of key stylized facts, including notably Zipf’s law for cities (which states that the number of cities of size greater than S is proportional to 1/S)...

This paper provides the first empirical test of the role of history versus expectations in U.S. urban development. Starting from Paul Krugman's theoretical work in new economic geography, we test whether or not a modern city develops because of either advantageous initial conditions or by way of...

Research in sociology and economics point to important role for social networks in labor markets. Social contacts mediate propagation of rich and reliable information among indi- viduals and thus help workers find jobs and employers find employees. Recent theoretical advances show that for...

This paper examines social interactions when social networking is endogenous. It employs a linear-quadratic model that accommodates contextual effects, and endogenous local inter- actions, that is where individuals react to the decisions of their neighbors, and endogenous global ones, where...