Donald Trump Has a Cost Estimate For His Border Wall to Send to Mexico

Donald Trump, who came up with a big win this week in the New Hampshire Republican primary, has been getting more specific about his plans to build a border wall between the US and Mexico.

The real estate mogul envisions hundreds of miles of precast concrete rising between 35 feet and 40 feet into the air, he told MSNBC in a Feb. 9 interview. It will be attractive, “you know, as good as a wall is going to look,” he said. The total cost will be around $8 billion, which will be billable to Mexico, according to the presidential candidate.

That number correlated nicely with the past costs of installing border barriers. Here’s what the US government has put up so far and how much it cost, according to government data. (Currently about a third of the 1,933-mile land border between the two countries has fencing of some kind.)

Trump’s estimate hits at the end of the $2.2 billion-$8.3 billion range it would cost to cover the rest of the border at those costs. (He told MSNBC that he arrived at that figure by multiplying the number of miles by the price per square foot.)

But his projection does not include a variety of other factors that would make a wall much more expensive.

For starters, some of the existing fencing is already in more easily accessible areas, meaning building it was probably much cheaper than it would be in the inhospitable and remote terrain that remains open.

And there are other kinds of expenses to consider. For example, the US government would likely incur in legal fees associated with lawsuits filed to secure the land on which to build the wall. Fighting environmentalists trying to preserve the free transit of wildlife between the two countries also could be costly.

Also, sealing the border would no doubt damage the US’s relations with Mexico, it’s third-largest trading partner, which could have an economic cost. Trump appears not to be overly concerned with that, given that he sees the US’s current $58.3 billion trade deficit with Mexico as “astronomical,” per the MSNBC interview. But this figure doesn’t reflect the fact that because of cross-border manufacturing, around 40% of the components of US imports from Mexico were originally produced in the US.

In the end, though, Trump’s biggest miscalculation isn’t the price of his pet project, but his assumption that the Mexican government will pay for it. Last week, former Mexican president Felipe Calderón said Mexicans “are not going to pay any single cent for such a stupid wall,” CNBC reported.