DHS Secretary Janet Napolitano has complained on more than one occasion that Republicans are “moving the goalposts” when it comes to border security. The administration, she argues, has made great progress in securing the southern border but is given no credit for that progress.

One reason, as former DHS economist Bryan Roberts and I argue in a new piece for Foreign Affairs, is that the current metrics for measuring progress at the border are lousy. The major piece of evidence Napolitano and CBP officials cite is the falling number of apprehensions at the border, a somewhat counterintuitive measure in which fewer arrests is a good thing, because more would-be illegal immigrants have supposedly been deterred from trying. No wonder it’s hard to persuade the Congress.

Bryan and I argue that without better metrics, the debate will remain bogged down in divisive debates over whether or not border security is improving. You can read more on this in the Foreign Affairs article, “Are U.S. Borders Safe?”