Regulatory reform is on the agenda for President Donald Trump’s first 100 days in office. At the forefront is Trump’s recent vow to institute a policy which would require two regulations to be repealed for every new regulation issued—a so-called two-for-one system. Although Canada, the United Kingdom, Australia, and the Netherlands have adopted regulatory offset programs like the kind Trump has proposed, it is unclear how, exactly, a similar system could be implemented in the United States. As Cass Sunstein of Harvard Law School recently remarked, the idea of a one-in-two-out system has “rhetorical appeal, but it’s going to be extremely hard to pull off.” Which regulations would need to be offset, and how would offsets be calculated? A re...