Supply Shock
A sudden unexpected event that significantly disrupts the supply of a key commodity or input.
What is Supply Shock?
A supply shock is an unexpected event that abruptly alters the supply of a major input or commodity, causing rapid shifts in prices and economic output. Negative supply shocks — such as the 1973 OPEC oil embargo, pandemic-induced supply chain disruptions, or crop failures — reduce supply, driving prices up while simultaneously reducing economic output, a painful combination called stagflation. Positive supply shocks — such as technological breakthroughs that lower production costs — expand supply, lowering prices and boosting output. Supply shocks create a difficult dilemma for central banks: the standard rate-hiking response to fight inflation also worsens the output decline, forcing a choice between controlling prices and supporting growth.
Example
In October 1973, OPEC imposed an oil embargo on the U.S. in response to American support for Israel in the Yom Kippur War. Oil prices quadrupled within months. U.S. gasoline prices surged, manufacturing costs rose across every sector, and GDP contracted — all simultaneously. The Fed's attempt to fight inflation with higher rates deepened the recession. The episode demonstrated how a negative supply shock can produce inflation and recession at the same time.