The economy is always at its short-run equilibrium: the point where aggregate demand (AD) crosses short-run aggregate supply (SRAS). That intersection tells you the economy's current real GDP and current price level.
Long-run equilibrium is a stricter condition: AD, SRAS, and long-run aggregate supply (LRAS) all pass through the same point. LRAS is vertical at potential output (Yf) — also called full-employment output — because in the long run wages and all prices fully adjust, so output depends only on the economy's resources, technology, and institutions, not on the price level. At Yf, unemployment sits at its natural rate (frictional + structural, zero cyclical).
Only real factors move LRAS: labor force growth, capital accumulation, productivity gains. Consumer confidence, government stimulus, and the money supply move AD, never LRAS. Demand does not build factories.
When the short-run equilibrium is not on the LRAS line, the economy has an output gap:
| Gap | Condition | Labor market | Typical cause |
|---|---|---|---|
| Recessionary gap | Current output < Yf | Unemployment above the natural rate (positive cyclical unemployment) | AD fell (or a negative supply shock) |
| Inflationary gap | Current output > Yf | Unemployment below the natural rate (tight labor market) | AD boom |
Two reading rules the CLEP exam tests directly:
[GRAPH: Recessionary gap
X-axis: Real GDP (Y) Y-axis: Price level (PL)
Curves: LRAS vertical at Yf; AD and SRAS crossing at Y1 LEFT of LRAS
Equilibrium at (Y1, PL1) with Y1 < Yf; horizontal distance Y1 to Yf
labeled "recessionary gap"]
[GRAPH: Inflationary gap — mirror image
AD and SRAS cross at Y1 RIGHT of LRAS; distance Yf to Y1 labeled
"inflationary gap"]
With no policy action, the economy eventually returns to Yf through wage adjustment shifting SRAS — never through AD moving back on its own.
Closing a recessionary gap: unemployment above the natural rate → slack labor market → nominal wages eventually fall → production costs fall → SRAS shifts right → output returns to Yf at a lower price level.
Closing an inflationary gap: unemployment below the natural rate → employers bid for scarce workers → nominal wages rise → costs rise → SRAS shifts left → output returns to Yf at a higher price level.
[GRAPH: Self-correction from a recessionary gap
Start: AD ∩ SRAS1 at (Y1, PL1), left of LRAS
Adjustment: wages fall → SRAS1 shifts right to SRAS2
End: AD ∩ SRAS2 on LRAS at (Yf, PL2 < PL1)]
Two consequences worth memorizing:
Exam questions flip freely between the two. Translate instantly:
A recessionary gap does not mean potential output fell. Potential changes only when resources or technology change (a hurricane destroying capital, yes; a drop in home-buying confidence, no). Ordinary recessions idle capacity; they don't destroy it.
1. C. With wages and all prices fully flexible, a change in the price level changes nothing real — output is pinned by resources and technology, so LRAS is vertical. A: the long run doesn't hold the price level constant; it frees every price to adjust. B: demand sets short-run position and long-run prices, not potential output. D: the long run is precisely when firms can change everything. E: the money supply's growth path doesn't define LRAS.
Fix: Vertical LRAS = "in the long run, output is a real phenomenon, not a nominal one."
2. D. The economy's current position is always where AD crosses SRAS. A: AD∩LRAS has no special meaning unless SRAS also passes through it. B: SRAS∩LRAS ignores demand entirely. C: all three curves meeting is the long-run equilibrium condition, a stricter case. E: that's the money market, a different graph.
Fix: Short-run equilibrium = AD∩SRAS, always; long-run adds the requirement that the point sits on LRAS.
3. E. AD∩SRAS right of LRAS = output above potential = inflationary gap, and unemployment below the natural rate in the overheated labor market. A: left of LRAS is the recessionary case. B: long-run equilibrium requires the intersection ON the LRAS line. C: mixes the gap label with the wrong labor market. D: names the gap correctly but reverses the unemployment direction.
Fix: Gap identification is geometric — left of LRAS = recessionary, right = inflationary — and the unemployment direction is always the mirror of the output direction.
4. B. Producing below potential means some workers who would be employed at full employment are idle: cyclical unemployment is positive, so total unemployment exceeds the natural rate. A: the natural rate holds only at potential output. C: below-natural unemployment belongs to inflationary gaps. D: unemployment is never zero — frictional and structural unemployment always exist. E: cyclical unemployment is added on top of frictional (and structural), not replaced by it.
Fix: Output below potential ↔ unemployment above natural — translate output language into labor-market language instantly.
5. A. Slack labor markets eventually push nominal wages down, cutting production costs and shifting SRAS rightward until output is restored at Yf with a lower price level. B: AD stays put absent policy — self-correction is a supply-side story. C: LRAS doesn't chase demand; capacity is unchanged. D: wages rising is the inflationary-gap adjustment, backwards here. E: the price level ends lower, not higher, and it is a result of the SRAS shift, not an independent cause.
Fix: No-policy adjustment = wages move → SRAS moves; if you shifted AD, you described policy, not self-correction.
6. E. AD shifts right along an upward-sloping SRAS: output and the price level both rise, pushing output beyond Yf — an inflationary gap. A: an unchanged price level would require a horizontal SRAS. B: both directions wrong. C: LRAS constrains the long run; the short run moves. D: output rises, not falls, when demand increases.
Fix: Short-run effects of an AD shift come from sliding along SRAS — demand up means output and price level both up.
7. E. The inflationary gap tightens the labor market, wages rise, SRAS shifts left, and the economy lands back on LRAS at Yf — with a permanently higher price level. A/B: output gains do not survive the long run. C: an AD increase ends with a higher, not lower, price level. D: output returns to potential, not below it.
Fix: In the long run, AD shifts change only the price level — Yf is untouched.
8. D. Contracts, salary norms, minimum wages, and morale make nominal pay cuts rare, so the wages-fall → SRAS-right adjustment stalls — the standard case for policy intervention. A: no law freezes the price level; it's wages that resist falling. B: LRAS doesn't move in an ordinary recession. C: AD falling further is a possible complication, not the core reason the wage mechanism is slow. E: the model treats the natural rate as stable.
Fix: Self-correction is asymmetric — wages rise easily (inflationary gaps close fast) but fall grudgingly (recessionary gaps linger).
9. C. Current output and the current price level are read at AD∩SRAS: $14 trillion, which is $1 trillion below the $15 trillion potential — a recessionary gap. A: LRAS marks potential, not the economy's position. B: no averaging is involved. D: $1 trillion is the gap's size, not current output. E: the intersection already fixes both output and the price level.
Fix: "Current output" always means the AD∩SRAS point; never report the LRAS value as the economy's position.
10. A. Gaps measure position relative to an unchanged potential; LRAS moves only when resources, technology, or institutions change. B: gaps are defined by where AD∩SRAS falls relative to a fixed LRAS. C: ordinary recessions idle capacity rather than destroy it. D: that reverses the definition — exceeding potential is the inflationary case. E: potential can change (growth, disasters); it just didn't here.
Fix: Recessionary gap = operating inside unchanged capacity; falling potential = the capacity itself shrank — different diagnoses.
11. D. With unemployment below the natural rate, employers bid up wages, costs rise, and SRAS shifts left until AD∩SRAS returns to the LRAS line at a higher price level. A: AD doesn't retreat on its own. B: LRAS doesn't expand to validate a demand boom. C: wages rise in a tight market — falling wages is the recessionary-gap story. E: the price level ends higher after this adjustment, not restored.
Fix: Inflationary gap closes via wages up → SRAS left → same Yf, higher price level.
12. B. Overtime, added shifts, postponed maintenance, and workers drawn in from outside the labor force let output run above potential temporarily; the wage adjustment in Q11 is what makes it temporary. A: potential is a sustainable ceiling, not a physical one. C: inflationary gaps are defined by output exceeding potential. D: "permanent" is exactly what the gap cannot be. E: inflationary gaps arise from demand booms, not from falling potential.
Fix: Above-potential output is unsustainable, not impossible — that distinction is the whole concept of an inflationary gap.
1. C. With wages and all prices fully flexible, a change in the price level changes nothing real — output is pinned by resources and technology, so LRAS is vertical. A: the long run doesn't hold the price level constant; it frees every price to adjust. B: demand sets short-run position and long-run prices, not potential output. D: the long run is precisely when firms can change everything. E: the money supply's growth path doesn't define LRAS. Fix: Vertical LRAS = "in the long run, output is a real phenomenon, not a nominal one."
2. D. The economy's current position is always where AD crosses SRAS. A: AD∩LRAS has no special meaning unless SRAS also passes through it. B: SRAS∩LRAS ignores demand entirely. C: all three curves meeting is the long-run equilibrium condition, a stricter case. E: that's the money market, a different graph. Fix: Short-run equilibrium = AD∩SRAS, always; long-run adds the requirement that the point sits on LRAS.
3. E. AD∩SRAS right of LRAS = output above potential = inflationary gap, and unemployment below the natural rate in the overheated labor market. A: left of LRAS is the recessionary case. B: long-run equilibrium requires the intersection ON the LRAS line. C: mixes the gap label with the wrong labor market. D: names the gap correctly but reverses the unemployment direction. Fix: Gap identification is geometric — left of LRAS = recessionary, right = inflationary — and the unemployment direction is always the mirror of the output direction.
4. B. Producing below potential means some workers who would be employed at full employment are idle: cyclical unemployment is positive, so total unemployment exceeds the natural rate. A: the natural rate holds only at potential output. C: below-natural unemployment belongs to inflationary gaps. D: unemployment is never zero — frictional and structural unemployment always exist. E: cyclical unemployment is added on top of frictional (and structural), not replaced by it. Fix: Output below potential ↔ unemployment above natural — translate output language into labor-market language instantly.
5. A. Slack labor markets eventually push nominal wages down, cutting production costs and shifting SRAS rightward until output is restored at Yf with a lower price level. B: AD stays put absent policy — self-correction is a supply-side story. C: LRAS doesn't chase demand; capacity is unchanged. D: wages rising is the inflationary-gap adjustment, backwards here. E: the price level ends lower, not higher, and it is a result of the SRAS shift, not an independent cause. Fix: No-policy adjustment = wages move → SRAS moves; if you shifted AD, you described policy, not self-correction.
6. E. AD shifts right along an upward-sloping SRAS: output and the price level both rise, pushing output beyond Yf — an inflationary gap. A: an unchanged price level would require a horizontal SRAS. B: both directions wrong. C: LRAS constrains the long run; the short run moves. D: output rises, not falls, when demand increases. Fix: Short-run effects of an AD shift come from sliding along SRAS — demand up means output and price level both up.
7. E. The inflationary gap tightens the labor market, wages rise, SRAS shifts left, and the economy lands back on LRAS at Yf — with a permanently higher price level. A/B: output gains do not survive the long run. C: an AD increase ends with a higher, not lower, price level. D: output returns to potential, not below it. Fix: In the long run, AD shifts change only the price level — Yf is untouched.
8. D. Contracts, salary norms, minimum wages, and morale make nominal pay cuts rare, so the wages-fall → SRAS-right adjustment stalls — the standard case for policy intervention. A: no law freezes the price level; it's wages that resist falling. B: LRAS doesn't move in an ordinary recession. C: AD falling further is a possible complication, not the core reason the wage mechanism is slow. E: the model treats the natural rate as stable. Fix: Self-correction is asymmetric — wages rise easily (inflationary gaps close fast) but fall grudgingly (recessionary gaps linger).
9. C. Current output and the current price level are read at AD∩SRAS: $14 trillion, which is $1 trillion below the $15 trillion potential — a recessionary gap. A: LRAS marks potential, not the economy's position. B: no averaging is involved. D: $1 trillion is the gap's size, not current output. E: the intersection already fixes both output and the price level. Fix: "Current output" always means the AD∩SRAS point; never report the LRAS value as the economy's position.
10. A. Gaps measure position relative to an unchanged potential; LRAS moves only when resources, technology, or institutions change. B: gaps are defined by where AD∩SRAS falls relative to a fixed LRAS. C: ordinary recessions idle capacity rather than destroy it. D: that reverses the definition — exceeding potential is the inflationary case. E: potential can change (growth, disasters); it just didn't here. Fix: Recessionary gap = operating inside unchanged capacity; falling potential = the capacity itself shrank — different diagnoses.
11. D. With unemployment below the natural rate, employers bid up wages, costs rise, and SRAS shifts left until AD∩SRAS returns to the LRAS line at a higher price level. A: AD doesn't retreat on its own. B: LRAS doesn't expand to validate a demand boom. C: wages rise in a tight market — falling wages is the recessionary-gap story. E: the price level ends higher after this adjustment, not restored. Fix: Inflationary gap closes via wages up → SRAS left → same Yf, higher price level.
12. B. Overtime, added shifts, postponed maintenance, and workers drawn in from outside the labor force let output run above potential temporarily; the wage adjustment in Q11 is what makes it temporary. A: potential is a sustainable ceiling, not a physical one. C: inflationary gaps are defined by output exceeding potential. D: "permanent" is exactly what the gap cannot be. E: inflationary gaps arise from demand booms, not from falling potential. Fix: Above-potential output is unsustainable, not impossible — that distinction is the whole concept of an inflationary gap.