Historically, urban growth required enough development to grow and transport significant agricultural surpluses or a government effective enough to build an empire. But there has been an explosion of poor mega-cities over the last thirty years. A simple urban model illustrates that in closed...

Gender-Based Taxation (GBT) satisfies Ramsey's rule of optimality because it taxes at a lower rate the more elastic labor supply of women. This holds when different elasticities between men and women are taken as exogenous. We study GBT in a model in which labor supply elasticities emerge...