Nearly all taxes impose hidden costs by choking off economic activity. In a soon-to-be-released Cato Institute study, Duke University professor Christopher J. Conover estimates how much economic activity the recently enacted health care law — the Patient Protection and Affordable Care Act — will destroy. Failing to account for those hidden costs of taxation and government spending can bias legislative decisions toward more costly policies. Conover argues that honest and transparent governance requires that Congress account for the “excess burden of taxation” in its legislative cost estimates, baseline budget projections, and budget options — much like the Office of Management and Budget already does.