Economists Timothy Hatton of the Australian National University, and Jeffrey Williamson of Harvard look at the potential impact of the global economic crisis on international migration in a new article at VoxEU. Immigration has a direct relationship with business cycles--when an economy is growing, immigration goes up--and "History leads us to expect a global recession to increase anti-immigrant sentiments and possibly spur new barriers to migration." But, they say things might be different this time around. Hatton and Williamson point to something called the 10 Percent Rule: where immigration policies are not restrictive, every 100 jobs lost in an economy means 10 fewer immigrants. This rule was in effect in as net immigration turned negative in places like the US, Canada, Australia, and Argentina during the depression of the 1890s and the Great Depression. Does the 10% rule apply today? On the one hand, migration should be less responsive to business cycle conditions when tough immigration policies are in place. On the other hand, those moving under family reunification (around half of US immigration) are much freer to move, and most recent migrants have the option to return home. It goes without saying that illegal immigrants are particularly sensitive to employment conditions. Figure 1 shows the relationship between the unemployment and the net immigration rate per thousand of the population (including illegal immigrants) for the US. It shows a striking inverse correlation. If the relationship between net immigration and employment is estimated – voila! – the 10% rule reappears. Ultimately, the key factor comes down to public response. Historically, recessions have led to anti-immigration sentiment. And while Hatton and Williamson argue that anti-immigration sentiment in OECD countries has not increased as much as it did in the late Nineteenth Century or during the Great Depression, they also say: History leads us to expect rising anti-immigrant sentiment in a global recession, and a deep recession would seem to provide the ingredients for a sharp immigration policy backlash. For some it would seem like the perfect opportunity to erect higher fences to insulate workers in the developed world from ever mounting flood of immigrants once the recession is over. But that flood is not ever-mounting. The current world crisis will reduce immigration, and the long-run pressure to immigrate will continue to ease after it is over. Read the full article here .