April 2000 - If urban overconcentration really is an issue, it ought to affect economic growth rates in a robust, consistent fashion. And it does. Not only is there an optimal degree of urban concentration that varies with country income, but departures from optimal concentration result in...

GDP growth is often measured poorly for countries and rarely measured at all for cities. We propose a readily available proxy: satellite data on lights at night. Our statistical framework uses light growth to supplement existing income growth measures. The framework is applied to countries with...