Why Policymakers Can’t Afford to Spurn the Science of Prediction

In recent months, Russian President Vladimir Putin’s nuclear saber rattling has forced observers and policymakers to try to figure out how seriously to take his threats. Unfortunately, few of the countless analyses published thus far have assessed the probability that Putin will use nuclear weapons in Ukraine in specific, quantitative terms. Most merely conclude that Putin is “likely” or “unlikely” to do so without defining what those words mean in the present context.

Although some imprecision is a function of the uncertainty inherent in a unique situation, much of it stems from a resistance to quantifying . . .