Tax Cuts and Growth, or Not

In yesterday's New York Times, Neil Irwin asks, "Do Tax Cuts Really Spur Growth?" I am quoted as follows:

“The basic finding in the literature is that it’s very hard to detect a robust impact from changing taxes to growth,” said Andrew Samwick, a Dartmouth economist who co-wrote a review of the evidence. “If you look across countries, unless they’re actually out there confiscating assets through their tax system, you don’t find a strong relationship.”

In other words, there are countries with high or rising taxes that have strong growth, and countries with low or falling rates that don’t.

The review in question is this paper with Bill Gale of the Brookings Institution, which has recently been published in a conference volume on The Economics of Tax Policy, edited by Alan Auerbach and Kent Smetters.

What I had in mind in the quote is this recent article by Nir Jaimovich and Sergio Rebelo, "Nonlinear Effects of Taxation on Growth," from the February issue of the Journal of Political Economy. Consider their abstract:

We propose a model consistent with two observations. First, the tax rates adopted by different countries are generally uncorrelated with their growth performance. Second, countries that drastically reduce private incentives to invest severely hurt their growth performance. In our model, the effects of taxation on growth are highly nonlinear. Low tax rates have a very small impact on long-run growth rates. But as tax rates rise, their negative impact on growth rises dramatically. The median voter chooses tax rates that have a small impact on growth prospects, making the relation between tax rates and economic growth difficult to measure empirically.

The notion that it is very hard to find a systematic effect of tax rates on long-term economic growth is common knowledge in academic circles. My favorite quote on the matter is a 20-year-old remark that Bill Easterly made in discussing this paper by Joel Slemrod, "... the data mock attempts to discern the growth effects of taxes ..."

Note that this is a different question than whether a cut in tax rates can spur economic activity in the short run. Reducing tax rates, without reducing current spending, can shift economic activity from the future to the present, and this will be measured as growth in the economy financed by an increase in debt. But this is not long-term economic growth. Economic activity will be lower in the future when either tax rates are increased to retire the debt or the interest payments to service the debt crowd out other spending. Shifting economic activity forward within a multi-year period is not economic growth when measured over the whole period.