Stagflation and Supply Shocks
Stagflation is the uncomfortable combination of high inflation and stagnant growth, typically triggered by a supply shock that raises costs without raising demand.
Stagflation is a combination that standard demand-driven models struggle to explain: inflation rising while growth stalls and unemployment climbs. It typically happens after a supply shock — something that makes production more expensive across the economy (an oil embargo, a war disrupting a key input, a pandemic snarling supply chains) rather than something that makes people want to buy more.
A demand shock pushes prices and output in the same direction; a supply shock pushes them in opposite directions — costs rise, so prices go up, but the same disruption also makes production harder, so output falls. That combination is stagflation.
Why it's hard for policymakers
Ordinary demand-side tools cut both ways here. Raising interest rates to fight the inflation slows growth further; cutting rates to support growth adds more fuel to inflation. There is no single lever that fixes both problems at once, which is what made the 1970s oil-shock episodes so difficult to manage compared to a garden-variety recession.
Worked example
Say an oil exporter cartel cuts output, tripling crude prices. Transportation and manufacturing costs jump economy-wide, so headline inflation rises from 3% to 9%. At the same time, higher input costs squeeze margins, and firms cut production and lay off workers, so GDP growth falls from 3% to -1% and unemployment rises from 4% to 7%. A central bank now faces 9% inflation and rising unemployment simultaneously — hiking rates to tame prices would push unemployment higher still, while cutting rates to support jobs would let inflation run further.
Not every inflation-plus-slowdown episode is "stagflation" in the classic sense — the term specifically implies a supply-side origin, and applying demand-side remedies (like a simple rate cut) to a supply shock can make the inflation problem worse without meaningfully fixing growth.
Practice in interviews
Further reading
- Blinder and Rudd, 'The Supply-Shock Explanation of the Great Stagflation Revisited'