Stagflation—the simultaneous occurrence of high inflation and high unemployment—creates a policy dilemma: expansionary policy reduces unemployment but raises inflation, while contractionary policy reduces inflation but increases unemployment. Successfully managing stagflation requires either eliminating the supply shock, shifting expectations (credibility of inflation targeting), or accepting a difficult tradeoff in the near term.
To understand why stagflation is so politically painful, recall what you learned about supply-side shocks. A negative supply shock — say, a sudden doubling of oil prices — does two things at once: it raises production costs across the economy (pushing inflation up) and it reduces the capacity to produce output (pushing unemployment up). On the aggregate supply-aggregate demand diagram, the short-run aggregate supply curve shifts leftward, landing the economy at a point with both higher prices and lower output. This is the stagflation corner: the two standard macroeconomic ills occurring simultaneously.
Now invoke the expectations-augmented Phillips curve. Under normal conditions, the Phillips curve implies a tradeoff: accept more inflation to get lower unemployment, or tighten policy to bring inflation down at the cost of higher unemployment. Stagflation breaks this tradeoff by moving the entire curve outward — higher inflation coexists with higher unemployment at every point. Policymakers face a genuine dilemma. If they respond to the high unemployment with expansionary fiscal or monetary policy, they validate the higher prices and risk accelerating inflation. If they respond to the high inflation with contractionary policy, they deepen the recession. There is no policy instrument that addresses both problems simultaneously; each tool helps on one dimension and worsens the other.
The 1970s oil shocks illustrated this conflict starkly. The OPEC oil embargoes created stagflation in the United States and Europe. Policymakers who tried to accommodate the supply shock by expanding money supply kept unemployment lower in the short run, but inflation expectations became entrenched — workers and firms began setting wages and prices based on anticipated high inflation, shifting the Phillips curve further outward. The result was a wage-price spiral in which inflation remained elevated long after the original shock. By contrast, the Volcker disinflation of 1979–1982 took the contractionary route: sharply raising interest rates crushed inflation at the cost of a deep recession, only gradually reanchoring expectations at lower levels.
The key insight is that long-run resolution depends on expectations management more than on the immediate policy response. A central bank with credibility — a demonstrated commitment to an inflation target — can reduce the sacrifice ratio (the unemployment cost of reducing inflation by one percentage point). When firms and workers believe that inflation will return to target, they set prices and wages accordingly, and the short-run Phillips curve shifts back inward without requiring a prolonged recession. This is why modern central banks invest heavily in communication, transparency, and institutional independence: the expectation of policy is itself a tool. Stagflation reveals that macroeconomic stability is a reputation problem as much as an instrument-selection problem.