Can negative supply shocks cause even larger demand shortages?
Core argument: The authors argue that a 100% supply shock concentrated in half the economy differs from a 50% shock spread across all sectors, with firm exits and job destruction amplifying the resulting recession.
The COVID-19 pandemic has highlighted how supply shocks can transform into larger demand shocks, termed "Keynesian supply shocks." When certain goods become unavailable, the shadow price of affected sectors rises, discouraging overall consumption. This can lead to a deflationary shock turning inflationary as future consumption becomes more valuable. In economies with multiple sectors, incomplete markets, and liquidity-constrained consumers, these shocks are more likely. A 50% shock across all sectors differs from a 100% shock in half the economy, with firm exits and job destruction amplifying the recession. As initial businesses close, demand for others drops, potentially causing further closures and layoffs, creating a multiplier effect that could shut down much of the economy. Standard fiscal stimulus may be less effective, but monetary policy can prevent firm exits. Optimal policy involves closing contact-intensive sectors and providing full insurance to affected workers to achieve the best allocation despite fiscal policy's lower potency.



