@ Lou
5. The Reinhardt and Rogoff work was, very publicly, debunked due to calculation mistake (as was the 90% threshold). It was embarrassing.
The Reinhardt and Rogoff study, of course, the one I cited claiming that economic growth is ridiculous by high debt thresholds, particularly above 90% of gdp. You said it was discredited, and it was, well...sort of.
However, Reinhardt and Rogoff did later admit to that and corrected what was a coding error.
The criticism or discrediting of the RR study was due to the work of Thomas Herndon, Michael Ash, and Robert Pollin of the Political Economy Research Institute at the University of Massachusetts....aka HAP.
Anyhow, R&R responded with another study in 2013 known as RR&R now. In it they did admit to error which they corrected. Now the eye opening thing about this RRR paper, it reached similar conclusions to the HAP work that discredited their 90% threshold in the first place.
The following is an article that was linked after the RR citation from the justfacts website I had referred to. I'll let it explain the rest.
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Do large national debts harm economies?
Advocates for higher government spending are abuzz over a new working paper that disputes a famous paper often trumpeted by conservatives. The famous paper found that high levels of national debt are associated with lower economic growth, a result that conservatives have repeatedly cited to argue that governments should stop accumulating debt.
This new working paper exposes calculation errors in the famous paper, critiques its methodology, and presents competing findings. Liberals have latched onto these findings to argue that nations should be less concerned with government debt and should increase government spending to “stimulate” their economies.
While the authors of the working paper make significant contributions to this debate, they and numerous commentators who are citing their work have used their findings to mislead rather than inform. They have done this by leveling false accusations, ignoring an important follow-up paper written by the same authors, and failing to reveal that the new findings are similar to that of the famous paper: high levels of national debt are associated with slower economic growth.
Primary Findings
For a
2010 paper published in the American Economic Review, Carmen M. Reinhart of the University of Maryland and Kenneth S. Rogoff of Harvard University researched and tabulated the national debt and economic growth in 20 advanced economies (such as the United States, France, and Japan). Using 2,000+ data points from over 200 years, the authors found that “high debt/GDP levels (90 percent and above) are associated with notably lower growth outcomes.” Relevantly, U.S. federal debt surpassed 90% of GDP in 2010 and has now reached 105% of GDP.
However, Reinhart and Rogoff’s paper has come under withering criticism in a
working paper written by Thomas Herndon, Michael Ash, and Robert Pollin of the Political Economy Research Institute at the University of Massachusetts, Amherst. Herndon, Ash, and Pollin [HAP] assert that the Reinhart and Rogoff [RR] paper suffers from “coding errors, selective exclusion of available data, and unconventional weighting of summary statistics,” which “lead to serious errors that inaccurately represent the relationship between public debt and GDP growth….”
The existence of at least one coding error is a reality that RR admit is “a significant mistake in one of our figures….” Furthermore, this coding error appears to pervade the entire paper, a point that RR have yet to formally acknowledge. Beyond this, the other issues raised by HAP boil down to subjective interpretations of how data should be averaged and the use of data that was not verified until after RR’s paper was published.
Most importantly, even if one uncritically accepts all of HAP’s methods, their primary results are basically similar to RR’s: countries with debt/GDP ratios higher than 90% have notably lower economic growth. HAP’s results are graphed here:
Misrepresenting the Results
Despite the association between debt and economic growth found by HAP, reporters and commentators have been leading their audiences to believe no such relationship exists. For example, Ben White and Tarini Parti of Politico reported that RR’s paper underwent a “very public demolition” at the hands of HAP, who found that economic growth “in countries with debt over 90 percent of GDP was around 2.2 percent, not much different from lower debt countries.”
In fact, HAP found that advanced countries with national debts over 90% of GDP had 31% less economic growth than when their debts were 60-90% of GDP, 29% less growth than when their debts were 30-60% of GDP, and 48% less growth than when their debts were 0-30% of GDP. As explained further below, these are significant differences with important implications, and Politico is not alone in masking these realities.
The Washington Post‘s editorial board wrote that HAP’s paper “debunks” RR’s “famous 2010 finding that a national debt-to-gross domestic product ratio above 90 percent may substantially moron economic growth.” A headline in the American Prospect has declared that “Reinhart and Rogoff’s Theory of Government Debt is Dead,” and Mike Konczal of the Roosevelt Institute has claimed that “one of the core empirical points providing the intellectual foundation for the global move to austerity in the early 2010s was based on someone accidentally not updating a row formula in Excel.” Countless other individuals and organizations have made similar claims.
These misrepresentations are somewhat understandable given the manner in which HAP present their findings. Their abstract denies any association between debt and economic growth, claiming that “average GDP growth at public debt/GDP ratios over 90 percent is not dramatically different than when debt/GDP ratios are lower.” What do they mean by “dramatically different?” One has to read ten pages into HAP’s paper before they provide a side-by-side comparison of the figures they arrived at for economic growth under different levels of debt: “The actual growth gap between the highest and next highest debt/GDP categories is 1.0 percentage point (i.e., 3.2 percent less 2.2 percent).”
To those unfamiliar with this issue, “1.0 percentage point” may not sound like much, but in this context, it amounts to 31% less economic growth per year. Compounded over time, this can cause genuine harm to people. For example, if economic growth in the U.S. were reduced by 1.0 percentage point per year over the past 20 years, GDP would have been $13.1 trillion in 2012 instead of the $15.7 trillion that it was. This portends far-reaching negative consequences, such as more poverty and reduced life expectancy. As explained in the textbook Microeconomics for Today:
"GDP per capita provides a general index of a country’s standard of living. Countries with low GDP per capita and slow growth in GDP per capita are less able to satisfy basic needs for food, shelter, clothing, education, and health."
In a recent New York Times op-ed, Pollin and Ash (two thirds of HAP) write that a “coding error and partial exclusion of data” by RR altered one of their results for economic growth by 0.6 percentage points. They perceptively note that this difference “is quite substantial when we’re talking about national economic growth.” Yet, in their paper, HAP characterize a much larger 1.0 percentage point difference in national economic growth as “not dramatically different.”
Cause and Effect
One of the most important critiques of RR and those who have favorably cited their research concerns the issue of causality. In basic terms, HAP and company argue that slow economic growth causes high debt and not vice-versa. In the words of Mark Gongloff of the Huffington Post, RR “imply strongly that high debt causes slow growth, when there is no evidence for that.”
In truth, there is prominent evidence for this, but HAP and many others have ignored it. In 2012, the Journal of Economic Perspectives published a paper by RR and Reinhart’s husband, Vincent R. Reinhart, the chief U.S. economist at Morgan Stanley. In this paper, these scholars (hereafter referred to as RRR) specifically addressed the issue of cause and effect. Yet, from reading HAP’s paper and many news reports and commentaries about this issue, one would never even know that this paper existed.
RRR took a straightforward approach to the matter of cause and effect by limiting their analysis to “prolonged periods of exceptionally high public debt, defined as episodes where public debt to GDP exceeded 90 percent for at least five years.” They found that these countries averaged 1.2 percentage points or 34% less economic growth than when debt was below 90% of GDP. Note that this figure is very close to the 31% difference found by HAP. RRR explain the significance of this with regard to cause and effect:
Following Reinhart and Rogoff (2010), we select stretches where gross public debt exceeds 90 percent of nominal GDP on a sustained basis. Such public debt overhang episodes are associated with lower growth than during other periods. Even more striking, among the 26 episodes we identify, 20 lasted more than a decade. The long duration belies the view that the correlation is caused mainly by debt buildups during business cycle recessions.
RRR emphasize that the cause-and-effect issue has not been “definitively addressed,” but they assert that “the balance of the existing evidence” from their study and other recent studies “certainly suggests that public debt above a certain threshold leads to a rate of economic growth that is perhaps 1 percentage point slower per year.” This is precisely the figure arrived at by HAP.
This does not mean that cause and effect can’t run in both directions. No one disputes that economic recessions can increase government debt, and constructive debate over this matter will surely be ongoing. Nonetheless, there is a clear association between high debt and slow growth, and substantial evidence that the former can cause the latter.
continued....
Summary
Condensing the key points above, there is a clear relationship between high levels of debt and slow economic growth. This is a not a universal rule but a robust association based upon extensive observations and disparate mathematical methods. The precise strength of this relationship is debatable, but existing results center around the outcome that growth in countries with debt over 90% of GDP is about 30% lower than when debt is below this level. There is also considerable but not definitive evidence that high debt can cause slow growth, as well as vice versa.
The current U.S. debt is at 105% of GDP and is projected to keep growing under current polices. This elevated level of debt may be a factor in weak economic growth that the U.S. has been experiencing, but advocates for increased government spending are blaming this and other problems on reduced government spending. This is in spite of the fact that since 2008, government spending has been much higher than it has been for the vast majority of U.S. history.