"The Economics of Immigration summarizes the best social science studying the actual impact of immigration, which is found to be at odds with popular fears. Greater flows of immigration have the potential to substantially increase world income and reduce extreme poverty. Existing evidence...

There is a tension between libertarians’ optimism about private supply of public goods and skepticism of the viability of voluntary collusion (Cowen 1992, Cowen and Sutter 1999). Playing off this asymmetry, Cowen (1992) advances the novel argument that the “free market in defense services”...