"We examine some basic data on the evolution of aggregate short interest, both during the dot-com era, and at other times in history. Total short interest moves in a countercyclical fashion. For example, short interest in NASDAQ stocks actually declines as the NASDAQ index approaches its peak....

We develop a standard search-matching model in which mobility costs are so high that it is too costly for workers to relocate when a change in their employment status occurs. We show that, in equilibrium, wages increase with distance to jobs and commuting costs because firms need to compensate...

We consider a search-matching model in which black workers are discriminated against and the job arrival rates of all workers depend on social networks as well as distance to jobs. Location choices are driven by the racial preferences of households (both blacks and whites) consciously choosing...