Immigration is once again a policy topic, so it is good to apply a bit of arithmetic to proposed solutions. It is best to begin with legal immigration, where much of the later problems and costs accrue.

Legal immigrants to the United States are generally better educated, work at higher rates and earn more than native-born citizens. Given how hard it is to enter the U.S. legally, this should be unsurprising; only educated and relatively wealthy folks can afford to apply. This means poorer folks with similar lofty and, dare I say, traditionally American ambitions have little choice but to come here illegally.

Most estimates suggest a whopping 11 million illegal immigrants are in the U.S. That is fewer than four in every 100 people walking the streets, and here in Indiana that means a typical very large high school will have seven or eight illegal immigrant students in each grade.

This illegal immigration has both benefits and costs. The benefits should be obvious, as most of these folks want to work. They pay sales and property taxes, licensing fees on that work. Many, but by no means all, also pay payroll and income taxes. Like about half of native-born citizens, the typical illegal immigrant costs taxpayers more than they'll pay in taxes over a lifetime. So what to do about that?

We could, of course, revise the immigration system and tax laws. We could craft a system that accommodates more temporary workers and collect more taxes on these folks. We could even charge a fine or fee for those who entered illegally, but who have afterwards been law-abiding citizens. This would enable us to more easily deport the folks who are actual criminals and allow us to support communities with high concentrations of immigrants. I don’t think that idea will be much talked about, though. It is too easy, sensible and cost effective. Instead we hear calls for mass deportation. Let me briefly analyze such a proposal.

A commercial bus ride from Chicago to Brownsville, Texas can be had for $198. So, if all of our illegal immigrants agreed to leave voluntarily, and Uncle Sam paid the bill, it’d be a bit over $2.1 billion. This is high fantasy though. By my calculations this trip will require about a third of the 840,000 registered busses in the U.S., most of which are those big yellow ones that drive through my neighborhood five days a week. So, we’ll have to plan this exodus in the summer, and it’ll cost more than $200 per deportee. The studies I have seen calculate the current cost of deportation from between $12,000 and $24,000 per person. That raises the costs of deportation to between $132 billion and $253 billion. This won’t catch the bad guys though, they are too slippery.

Of course, most of those who argue for full deportation know this is an impossible plan. So, when someone tells you they support deporting all our illegal immigrants, it isn’t that they are stupid enough to believe it. They just think you are.