While there has been strong promotion of free global trade in goods and services as well as in capital inputs, the case has not been made so forcefully for increasing the international mobility of the other factor of production, labor. A recent article in The Economist, Free Exchange—Border Follies, surveys the latest research on the potential benefits of increasing international labor migration (The Economist 17 November 2012). The estimates are staggering, with possible increases in world output and income ranging from 30% to 100% (amounting to an additional $20 trillion to $70 trillion) depending on the level of migration assumed. These calculations swamp the potential benefits of increasing international trade, which is estimated to be less than 3% of global output. The research shows that the gains come from migration-induced productivity increases in the host country and the additional incomes are more than sufficient to compensate for any adverse effects, for example, if wages for some host country workers fall in the short term. Remittances (worth around $300 billion a year) are also sent to the migrant source countries to compensate those who stay behind.