I’ve made no secret of my opinion that enhanced efforts at the border are less important than other measures in regaining control over immigration. I think the enforcement benefit of the next dollar we spend would be greater in, say, implementing an exit-tracking system. But the idea that we can’t afford a border wall has never struck me as plausible.


Well, it became even less plausible when my colleague Steven Camarota ran the numbers. It turns out that if a wall reduces the expected illegal flow by just 9-12 percent over the next decade, the wall will pay for itself.

The report is based on data from the National Academies of Sciences, the Institute for Defense Analyses, and the Heritage Foundation. It estimates that each illegal border-crosser represents a net fiscal drain of nearly $75,000. (Including their children would make the drain even larger.) If the border wall prevented 160,000 to 200,000 illegal crossings over the next decade (out of a projected 10-year total of 1.7 million successful infiltrations), it would be enough to cover the estimated $12 to $15 billion in construction costs.

There are caveats and qualifications, though they cut both ways. The NAS based its cost estimates on “net present value,” meaning it discounts future costs; the savings would be even greater using a different accounting method. On the other hand, half of new illegal aliens are visa overstayers, to whom a wall is irrelevant. What’s more, the wall will be built with federal funds, while much of the cost of immigration – and thus the savings from better enforcement – is borne by state and local governments (which will probably just squander the windfall).


But no tweak of the numbers can change the basic fact that letting unskilled people settle in the United States costs taxpayers a pile of money. And letting fewer in will save money. So even without a remittances tax or a hike in visa fees, even a minimally effective wall won’t in the end cost American taxpayers anything. That may not be as sexy as “Mexico will pay for it,” but it’s good enough for government work.