ジョージ・メイソン大のMercatus Centerの表題のコメンタリー記事(原題は「Why a Hot New Idea in Economics is Actually a Bad Idea」)で、スコット・サムナーがMMT批判している(共著者はPatrick Horan、H/T Mostly Economics*1

In recent years, a radical and unorthodox school of thought called “Modern Monetary Theory” (MMT) has become popular with some progressive economists, as well as with policymakers and activists on the political left. One of MMT’s most prominent advocates is Stephanie Kelton, a professor at Stony Brook University who advised Senator Bernie Sanders during his 2016 presidential run. The theory has received enough traction that the popular Planet Money podcast recently ran an episode on the topic.


Market monetarists argue that nominal GDP (total dollar spending on all goods and services in the economy) is the best way to determine whether monetary policy is too tight (leading to a recession) or too loose (leading to high inflation). During the recovery from the Great Recession, nominal GDP growth has averaged only four percent per year, which largely explains the low inflation rate. The 1980s was also a period of expansionary fiscal policy and rising government debt, and inflation also fell during this period, as the Fed reduced the growth rate of the money supply. And contrary to the predictions of MMT, the expansionary monetary policy of the 1960s and 1970s pushed inflation sharply higher, even though government spending and deficits were not unusually large. While the market monetarist model (as well as some other conventional models) can explain why inflation has remained near two percent since 1990, MMT has no clear explanation for the relative success of inflation targeting.


...Paul Krugman and other MMT critics have warned that money-financed debt could lead to hyperinflation. As Krugman wrote in 2011:
“When people expect inflation, they become reluctant to hold cash, which drive prices up and means that the government has to print more money to extract a given amount of real resources, which means higher inflation, etc... Do the math, and it becomes clear that any attempt to extract too much from seigniorage — more than a few percent of GDP, probably — leads to an infinite upward spiral in inflation. In effect, the currency is destroyed.”
MMTers might respond that what they are calling for in the US is nowhere near what the governments in Zimbabwe, Argentina, and Venezuela have done, so it’s unreasonable to claim that we’d see similarly high inflation. In fairness, the United States has much stronger institutions and less corruption than those countries. Nonetheless, as Krugman and others have pointed out, attempting to implement an MMT program of money-financed government spending would risk triggering an excessively sharp increase in inflation, especially as the economy strengthens. Experience shows that when inflation gets out of control, it leads to many other economic and social problems, from the erosion of people’s savings to political turmoil. The MMT agenda is not an experiment worth risking.



*1:cf. 両者の過去の因縁

*2:cf. Stephanie Kelton - Wikipediaここで紹介したレポートの著者の一人。同レポートの共著者の一人であるRandall Wrayが共同編集長となっている「Journal of Post Keynesian Economics」の編集委員務めている(実際のところ、同レポートの5人の著者のうち1人を除く全員がこの学術誌の編集に関わっている)。

*3:cf. Planet Money - Wikipedia