Harry Truman famously asked for a one-handed economist since all of his seemed reluctant to decisively answer anything: “on the one hand,” they’d tell him, but “on the other…”
When asked whether an income tax makes people work more or less, the typical economist gives the sort of answer that would have grated on Truman like a bad music critic.
If, however, we change the question slightly and make it more realistic, it’s possible to give a decisive answer to the question. Income taxes do reduce overall labor supply. This is something that economists James Gwartney and Richard Stroup explained in the pages of the American Economic Review some 30 years ago. And last week, the CBO’s much-discussed report on the ACA and labor-force participation illustrated their point nicely.