Is disinflation exogenous or the result of monetary policy?

Central banks (we look at the Federal Reserve and the ECB) welcome the fact that the shift to a more restrictive monetary policy has led to a fall in core inflation. But has monetary policy really had an effect on core inflation from 2022 to 2024, or is the decline in core inflation due only to exogenous causes? The unemployment rate has risen only slightly in the United States and not at all in the euro zone: the Phillips curve effect (link between unemployment rate and inflation) cannot therefore be used as an explanation; In the euro zone, but not in the United States, profit margins fell in 2023, which pushed down inflation . If we believe that this fall in profit margins is due to weak growth, and that weak growth is due to monetary policy (this is probably partly the case, given the decline in housing investment), there is a transmission channel in the euro zone from monetary policy to inflation; The fact remains that the fall in core inflation is due to the fall in industrial prices, which is linked to the fall in commodity prices. In total, 73% of the fall in core inflation in the United States and 33% of the fall in the euro zone is due to the fall in industrial prices, linked to the fall in commodity prices.