Michael Barone had an excellent piece in today’s Examiner where he wrote that the Mexican unauthorized immigration problem is going away because net Mexican migration is around zero for the first time since the Great Depression. Barone points out many reasons for this change: the size of the Mexican emigration cohort is remaining steady (Mexican women are about 1/3 as fertile in recent years as they were in 1970), U.S. economic growth is sluggish, sectors of the U.S. economy that employ unauthorized workers were some of the hardest hit in recent years, and Mexican economic growth is rapidly increasing incomes South of the border. All right so far.

But Barone is wrong to assume that just because Mexican unauthorized migration is abating that the problem will go away. For hundreds of millions of the world’s poor, the incentives to migrate remain. 

Immigration is mostly driven by economics. The cost of moving here (ignoring the cost of dealing with the U.S.government) is going to continue to fall while the benefits will remain high. Since 40 to 50 percent of unauthorized immigrants entered the U.S. legally and overstayed their visas, some unauthorized migrants don’t need to cross a harsh desert anymore. Migrant source countries are changing again but the flow won’t stop. 

Very poor countries don’t send many immigrants because the people there can’t afford to move. That’s why there aren’t many immigrants from the poorest nations of the world. People have to reach a certain level of prosperity before they can afford to migrate. After that point is reached, immigration continues until the gains from doing so shrink. The income gap between Mexico and the U.S. has narrowed so migration is slowing down on its own accord.

Other Central Americans still feel the economic pressure to migrate even if U.S. law doesn’t cooperate. This trend is reflected in the estimates of the unauthorized population compiled by the Department of Homeland Security. From 2000 to 2011 the unauthorized Mexican population increased by 45 percent. Over the same time the number of unauthorized Guatemalans increased by 82 percent and Hondurans by a whopping 132 percent. 

Human smugglers have many informal routes into the U.S. Until recently they’ve mostly been serving Mexicans but they are diversifying into other countries and finding migrants who will pay more. Smuggling prices are hard to come by since it’s illegal but anecdotal evidence suggests Chinese pay $75,000 per person and Indians pay around $20,000 to come to the U.S. illegally. 

The lack of a legal route for most potential migrants combined with a strict enforcement mechanism increases the costs and diminishes the benefits of migrating. But for millions the benefits of coming illegally still outweigh the costs of working in the informal economy. When economic growth in the U.S. recovers unauthorized immigration will also recover. The source countries for these immigrants may shift but at long as our immigration laws are restrictive and the benefits of coming here are greater than the costs, unauthorized immigration will persist.