The New Keynesian Phillips Curve is at the center of two raging empirical debates. First, how can purely forward looking pricing account for the observed persistence in aggregate inflation. Second, price-setting responds to movements in marginal costs, which should therefore be the driving force...

Suppose the nominal money supply could be cut literally overnight by, say, 20%. What would happen to prices, wages, output? The answer can be found in 1720s France, where just such an experiment was carried out, repeatedly. Prices adjusted instantaneously and fully on one market only, that for...