The policy world has turned on Ken Rogoff and Carmen Reinhart with a vengeance. The two are the celebrated authors of multiple studies showing that very high levels of government debt have historically been associated with slower growth. After a review of one of their articles revealed a spreadsheet mistake, the ever-temperate Paul Krugman was driven to ask: "Did an Excel coding error destroy the economies of the Western world?"
John Maynard Keynes once said that "even the most practical man of affairs is usually in the thrall of the ideas of some long-dead economist."Apparently, this bondage is felt even more acutely when those practical men are in the thrall of a living, breathing pair of economists. Now that Rogoff and Reinhart have been discredited, the thinking seems to go, the masses who had been suffering under the yoke of austerity are now free to spend as they had always wished.
There are a number of reasons to see this as an overreaction. The episode is a bit analogous to a researcher finding that a daily Twinkie adds 10 pounds over a year. A subsequent study finds that, with different methodology, a daily Twinkie might add only 5 pounds over a year. Then the baying pack howls that they knew Twinkies were good for you all along, they abjure dieting, and stuff themselves with cake and cream filling. [Reinhart and Rogoff respond to the criticisms and put the dispute in the context of a broader literature without resorting to any talk of dessert cakes.]
An odd strain of the discussion has been the implication that the only restraint on unbounded budget deficits has been the Reinhart-Rogoff admonition that it could slow economic growth. In fact, there are other constraints. How much can Portugal or Greece or Cyprus spend beyond current tax revenue? They can spend the money they have in savings (negligible) plus the amount they can borrow in the open market (negligible) plus the amount that other countries or international financial institutions (IMF, ECB) are willing to lend them. The limitation, then, is not Harvard researchers' findings but rather the willingness of other leaders to risk their funds, as their thoughts teem with admonitions about "sending good money after bad."
Of course, countries such as the United States, France, or the UK can borrow on open markets. That does not free them from all non-academic constraints, however. If borrowing is excessive, a country begins to look riskier. The United States was downgraded in 2011, France in 2012, and the UK last week. Even the IMF, cheering now for a spending boost, has argued for offsetting medium-run budget cuts.
The Reinhart-Rogoff episode has prompted deeper ruminations about how grounded our economic beliefs really are. In the Wall Street Journal, Carl Bialik elicits a confession from the editor of the American Economic Review that peer review rarely involves line-by-line checks of authors' calculations. Bialik lays bare some of the inherent vagaries of working with historical macroeconomic data -- there are no controlled experiments and the numbers can be unreliable.
It is thoroughly healthy to review the limitations of empirical macroeconomics. It is the part of economics that deals with the most moving parts and has the least opportunity to isolate treatment effects from confounding variables. Economics does far better as a field when conditions are more favorable -- predicting how an auction will work, for example. Yet citizens and policymakers want to know what will happen with inflation, unemployment, and growth, and how these will be affected by government spending, taxes, and the money supply. These are all macroeconomic questions.
Let's stipulate, then, that macroeconomic point estimates should be treated as somewhat fuzzy. That was always acknowledged in the formal economics (standard errors), but it does not usually make for good newspaper copy. If multiple studies, using different data sources and different techniques, find similar results, then we will have steadily more confidence in those findings. This has always been true too, though in public debate participants tend to prefer a single bold study to a lengthy lit review.
The newfound caution about macroeconomic findings has, so far, been curiously selective. Foes of austerity argue that, after slaying the dreaded Reinhart-Rogoff result, they are not even bound by warnings of credit downgrades. After all, if only we adopt new fiscal stimulus, it will promote growth and pay for itself (debt/GDP will fall as GDP rises faster than debt).
How do we know this? Why should we believe that the stimulative effects of new spending will overcome people's worries about the new taxes that will inevitably follow? How can we calculate how much stimulus is appropriate? Are tax cuts or spending increases more appropriate? If we do not see booming economic growth after stimulus has been tried, how will we know that the stimulus was worthwhile, that it saved us from an even worse fate?
We have macroeconomic findings. Precisely calculated macroeconomic findings. Based on historical data. Published in peer-reviewed journals. Worked out on spreadsheets. Let the spending commence.