(Since this chart was made, the U.K. rate has become 21 percent and Canada’s rate has risen to 26.3 percent.)The Treasury regulations, the anti-hopscotching one specifically, could slow some inversions that businesses are pursuing solely to reduce their effective tax rates.

The recent spate of inversions occurred because U.S. and foreign businesses recognized strong potential synergies in each other that made a merger appealing. They decided to invert, or locate the new business’s headquarters outside the U.S., after deciding a merger made economic and business sense.

It makes little sense to locate a company in the U.S. after a cross-border merger in the U.S. because the worldwide system in the U.S. would subject all the newly merged business’ foreign income to U.S. tax at the highest corporate tax rate in the industrialized world. The Treasury regulations do nothing to address this problem.

The solution to inversions remains tax reform that abolishes the worldwide system of taxing multinational businesses, moves to a territorial one and reduces the corporate tax rate. That will require action by Congress. The Obama administration should put its efforts into making tax reform a reality by working with and leading Congress, rather than wasting time with ineffective regulations.