There is an apparently technical but actually crucial point that I would like to make before getting to the crux of the matter. To assess a policy intervention (monetary or otherwise), one  1  From this perspective the Great Depression is considered an outlier, a unique historical event with limited general lessons on the cost of deflation.
2  See, inter alia, Neri and Notarpietro (2015). 2  BIS central bankers’ speeches  needs to look at the counterfactual and not, or not only, at the data. The question is not whether we are happy with the current levels of growth and inflation, but whether we would be happier if the interventions had not taken place at all.