In an editorial in Monday’s New York Times, Adam S. Posen, an American economist and a member of the Monetary Policy Committee of the Bank of England, provides an excellent illustration of the phenomenon of economists asserting that their policy preferences are literally scientific truth:
Scientific research tells us that high blood pressure and cholesterol are associated with a higher risk of heart disease and stroke, and that certain prescription medications reduce cholesterol and blood pressure. Yes, it is difficult to prove directly that taking these medicines prevents heart disease and stroke, and taking them is no guarantee of health. But still we should take them, and our doctors should prescribe them if they are indicated. This is the same situation we are in now, with our economy’s financial circulation at risk, and quantitative easing the indicated medicine. [Bold added]
Only it’s not quite “the same situation” at all.
Medical science has conducted randomized clinical trials that show precisely this link between cholesterol-reducing drugs and reductions in strokes and morbidity. For example, a 1999 meta-analysis of more than a dozen randomized experiments testing the effect of statins (cholesterol-lowering drugs) showed that that “on average one stroke is prevented for every 143 patients treated with statins over a 4-year period.”
Note that the first sentence of a Lancet paper describing one of the early experiments to establish the effect of a cholesterol-reducing drug on mortality is: “Drug therapy for hypercholesterolaemia has remained controversial mainly because of insufficient clinical trial evidence for improved survival.” Precisely the lack of such experimental evidence engendered a debate; resolution required experiments that established definitively the effects of the interventions.
We have nothing like this for quantitative easing. Lacking experimental evidence doesn’t mean that therefore we should not undertake quantitative easing, but the editorial is an attempt to browbeat opposition by appeal to a purported, but unsubstantiated, scientific authority.