A new report from the Commonwealth Institute, a liberal Virginia think tank, makes an excellent point. Virginia has enacted many special tax breaks over the years, but it does little in the way of follow-up. Why not? Government programs ought to undergo periodic review. They should not simply fly along on autopilot for decades, long after their original justification has outlived its usefulness. (Think of the national helium reserve or the mohair subsidy, both of which got their start in wars that ended decades ago. Does anyone expect the U.S. to conduct future air combat missions using blimps?)