We propose a spatial search-matching model where both job creation and job destruction are endogenous. Workers are ex ante identical but not ex post since their job can be hit by a technological shock, which decreases their productivity. They reside in a city and commuting to the job center...

We develop a model where information about jobs is essentially obtained through friends and relatives, i.e. strong and weak ties. Workers commute to a business center to work and to interact with other people. We find that housing prices increase with the level of social interactions in the city...

The make-or-buy decision is analyzed in a three-layer principal-management-agent model. There is a cost-saving/quality tradeoff in effort provision. The principal chooses between employing an in-house management and contracting with an independent management; the cost-saving incentives facing...

The make-or-buy decision is analyzed in a simple framework combining contractual incompleteness with the existence of imperfect but contractible performance measures. Contractual incompleteness gives rise to two regimes, identified with make and buy. The performance measure on which...

We survey the literature on social networks by putting together the economics, sociological and physics/applied mathematics approaches, showing their similarities and differences. We expose, in particular, the two main ways of modeling network formation. While the physics/applied mathematics...

We survey the literature on the economic consequences of the structure of social networks. We develop a taxonomy of "macro" and "micro" characteristics of social interaction networks and discuss both the theoretical and empirical findings concerning the role of those characteristics in...