Macroeconomic Equilibrium, Gaps, and Self-Correction

Chapter 11 companion lesson

An economy can operate below potential, at potential, or temporarily beyond potential. The distance from long-run capacity determines the gap and the direction of the wage-and-cost adjustment that follows.

Why does short-run equilibrium and the output gap matter?

Short-run macroeconomic equilibrium occurs where AD intersects SRAS. At that point, planned aggregate expenditure and firms' short-run production are compatible at a real GDP and price level. The outcome can lie below, at, or above potential output marked by LRAS.

The output gap compares equilibrium or actual real GDP with potential. A negative gap means output is below potential; a positive gap means output is above potential. If potential is 1,000 and equilibrium 940, the recessionary gap is 60. If equilibrium is 1,040, the inflationary gap is 40. Some sources express gaps as a percentage of potential: (Y-Yp)/Yp × 100.

A recessionary gap is associated with positive cyclical unemployment and downward pressure on wages and prices relative to the long-run equilibrium path. An inflationary gap is associated with unusually tight resource markets, negative cyclical unemployment in the simplified decomposition, and upward wage and price pressure.

How does the CLEP test recessionary-gap self-correction?

Suppose AD falls from long-run equilibrium. In the short run, the economy moves down along the existing SRAS curve: real GDP and the price level fall. Output is below potential and unemployment exceeds the natural rate. This is the first stage, not yet self-correction.

Weak labor demand and idle capacity put downward pressure on nominal wages and other input prices. Expectations of the price level can also adjust downward. Lower production costs make firms willing to supply more at every price level, shifting SRAS right. Output rises along the unchanged AD curve until SRAS intersects AD at LRAS.

After full adjustment, real GDP returns to the original potential if LRAS did not change. The price level is lower than before the demand shock. A permanent decrease in AD therefore changes the long-run price level, not long-run real output, in the basic model.

What should you know about inflationary-gap self-correction?

An increase in AD from long-run equilibrium raises real GDP and the price level in the short run. Output exceeds potential, unemployment falls below its natural rate, and labor and other resources become unusually scarce. Firms offer overtime and higher wages; suppliers raise input prices.

As nominal wages and expected prices rise, SRAS shifts left. Real GDP falls back toward potential along the new AD curve while the price level rises further. In long-run equilibrium, output returns to the original potential and the price level is higher than both the initial level and the short-run post-shock level.

This sequence explains long-run monetary neutrality in the basic model. A sustained one-time increase in nominal aggregate demand can temporarily raise real output, but after wages and prices fully adjust, nominal variables are higher and real output is determined by capacity. It does not imply monetary policy has no short-run effects or that all real-world adjustment is immediate.

How does the CLEP test supply shocks, policy tradeoffs, and changing potential?

An adverse supply shock shifts SRAS left from long-run equilibrium. Output falls below potential and the price level rises. Unlike a negative demand shock, the economy experiences inflation pressure alongside recession. If the shock is temporary and input costs later normalize, SRAS can return right. If wages eventually adjust downward because of the recessionary gap, self-correction can also move SRAS right, though the higher price level complicates the path.

Expansionary AD policy can restore output to potential but raises the price level further. Contractionary policy can offset price pressure but moves output farther below potential. Holding AD unchanged accepts temporary stagflation while supply adjusts. The model does not choose among objectives; it displays the tradeoff.

A favorable supply shock shifts SRAS right, raising output and lowering the price level. If productivity improved permanently, LRAS also shifts right and the higher output can be sustained. If the change was a temporary input-price decline, output above the old potential may not persist after the shock reverses.

What is the CLEP likely to ask?

Expect initial/short-run/long-run sequences, gap size, cyclical unemployment direction, self-correction through wages and SRAS, and policy shifts. Circle time words. A statement that is true after full adjustment can be wrong for an “initially'' question.

A useful check is to name the model before doing arithmetic. Then write the first change, the intermediate market response, and the final macroeconomic result. This keeps a plausible distractor from borrowing one true step and attaching it to the wrong conclusion.

Can you do these without notes?

1. Draw short-run equilibrium below, at, and above LRAS. For each, state the gap, cyclical unemployment direction, and wage-cost pressure.
2. Trace every variable from a leftward AD shock through passive long-run adjustment. Then compare the final price level under self-correction with the final price level under an AD-restoring policy.
3. Trace an AD increase through short and long runs. Explain why SRAS shifts left, why output returns to potential, and why the price level rises again during adjustment.

For each prompt, say why the tempting wrong answer fails. That extra sentence is often the difference between recognizing a term and being able to use it under time pressure.