Are regulatory costs overestimated or underestimated by academics and government types? Depends on the case, of course. But the conventional wisdom is that the bias is toward overestimation because, when push comes to shove, industry finds cheaper ways to the job done. In a new paper, though, EPA economist David Simpson questions that conclusion. It’s not a slam dunk—data are scarce. Still, we think his analysis adds a neat new angle to this debate.