The Supply-Side Effects of Monetary Policy

We propose a supply-side channel for the transmission of monetary policy. We show that in an economy with heterogeneous firms and endogenous markups, demand shocks have first-order effects on aggregate productivity. If high-markup firms have lower pass-throughs than low-markup firms, as is consistent with the empirical evidence, then a monetary easing reallocates resources to high-markup firms and alleviates misallocation. In this case, positive “demand shocks” are accompanied by endogenous positive “supply shocks” that raise output and productivity, lower inflation, and flatten the Phillips curve. We derive a tractable four-equation dynamic model and use it to show that monetary shocks generate a procyclical hump-shaped response in TFP and endogenous cost-push shocks in the New Keynesian Phillips curve. A calibration of the model suggests that the supply-side effect increases the half-life of a monetary shock’s effect on output by about 30% and amplifies the cumulative effect on output by about 70%. We provide empirical evidence of the micro-level reallocations that generate procyclical TFP using identified monetary shocks.