As the New York Times has documented, President Trump stated numerous times that Mexico would pay for the border wall. With this context, it was hard not to appreciate the delicious irony when EPA announced earlier this week that it would be financing two separate measures to reduce pollution migrating from Mexico to Southern California.

In other words, not only is Mexico not paying for the wall (and neither is Steve Bannon), but the United States is paying for pollution controls in Mexico! I actually happen to think that this is good news, but I doubt that President Trump is going to be trumpeting this accomplishment to his base. There’s a pretty persuasive argument to be made that avoiding pollution controls is one way that Mexico is able to produce goods more cheaply than the United States. And we’re now financing Mexico’s ability to undercut the price of US manufactured goods?

Instead of requiring Mexico to internalize the externality caused by loose environmental controls in Mexico, we’re subsidizing the externality.

Will wonders never cease?