R. Glenn Hubbard (Dean, Columbia Business School) has an op-ed in today’s Wall Street Journal, We Can’t Tax Our Way Out of the Entitlement Crisis:

Mr. Obama has revealed his plans in stages. First, on his campaign Web site, he indicated he would solve the long-run solvency of Social Security (a good thing). In a Sept. 21, 2007, op-ed in Iowa’s Quad-City Times, he ruled out benefit cuts to achieve solvency and looked first to payroll taxes (a bad thing). Last week, on this page, his economic advisers clarified his evolving tax proposals.

The spending shortfalls in Social Security and Medicare are large. According to the Congressional Budget Office, Social Security and Medicare spending left unchecked would, after a generation, consume about 10 percentage points more of GDP than it does today.

Simple arithmetic suggests that with this much more of GDP eaten up by the two programs, all federal taxes on average would have to be raised by more than 50% to make up the shortfall. Research by economists Eric Engen of the Federal Reserve Board and Jonathan Skinner of Dartmouth suggests that such a tax increase would reduce long-term GDP growth by about a full percentage point. This is no small matter: Think of it as reversing all of the gains in our long-term growth rate from the productivity boom of the past 15 years. …

The problem with Mr. Obama’s fiscal plans is not that that they lack vision. On the contrary, the vision is plain enough: a larger welfare state paid for by higher taxes. The problem is not even that they imply change. The problem is that his plans are statist.