In AP Macro, the output gap is the difference between actual output (real GDP) and potential output (full-employment GDP). A negative (recessionary) gap means output is below potential; a positive (inflationary) gap means output is above it (EK MEA-2.A.4).
The output gap measures how far an economy's actual real GDP sits from its potential output, the GDP the economy produces when unemployment equals the natural rate. Potential output is also called full-employment output, so an output gap is really a statement about jobs. If real GDP is below potential, unemployment is above the natural rate and you have a negative (recessionary) output gap. If real GDP is above potential, unemployment dips below the natural rate and you have a positive (inflationary) output gap.
Think of potential output as the economy's cruising speed. The business cycle is the economy constantly drifting above and below that speed, and the output gap is simply how far off cruising speed you are at any moment. On the AD-AS graph, the gap shows up as the horizontal distance between short-run equilibrium output (where AD crosses SRAS) and the LRAS curve. When AD and SRAS intersect right on LRAS, the gap is zero and the economy is in long-run equilibrium (EK MOD-2.G.2 and MOD-2.G.3).
The output gap lives in two places in the CED. In Unit 2 (Topic 2.7, Business Cycles), it's the measuring stick for where the economy is in the cycle, supporting AP Macro 2.7.A and 2.7.B. In Unit 3 (Topic 3.5, AD-AS Equilibrium), it becomes a graph, supporting AP Macro 3.5.A, where short-run equilibrium can sit at, above, or below full employment. This concept is the hinge between describing the economy and fixing it. Almost every fiscal and monetary policy question on the exam starts by asking which gap exists, because the gap tells you which direction policy should push AD.
Keep studying AP® Macroeconomics Unit 2
Recessionary Gap (Units 2-3)
A recessionary gap is just the negative output gap with a name. Real GDP is below potential, unemployment is above the natural rate, and the fix is expansionary policy. The 2019 SAQ literally opened with Canada 'in a recessionary output gap.'
Inflationary Gap (Units 2-3)
The positive output gap. The economy is producing beyond its sustainable capacity, unemployment falls below the natural rate, and inflation accelerates. It feels great short term, but the self-correction is rising wages shifting SRAS left.
Full-Employment Output (YF) (Units 2-3)
You can't have a gap without a benchmark. YF is the potential output you compare actual GDP against, and on the graph it's the vertical LRAS line. Output gap = actual GDP minus YF.
Business Cycle Phases (Unit 2)
The output gap translates the business cycle into numbers. During a recession the gap turns negative; during a strong expansion past the peak of potential, it turns positive. The cycle is the movie, the gap is the freeze-frame.
Output gaps show up two ways. MCQs give you numbers or labor-market clues and ask you to identify the gap. For example, actual output of $18 trillion against potential of $16 trillion is a positive (inflationary) gap, and a 3% unemployment rate below a 5% natural rate signals the same thing. FRQs go further. The 2023 FRQ Q1 gave Vanderlandia a real GDP of $500 million against full-employment GDP of $550 million and expected you to draw a correctly labeled AD-AS graph showing equilibrium left of LRAS. The 2019 and 2022 SAQs started economies in recessionary gaps and asked for the policy response. So your job is threefold. Identify the gap from data, draw it on an AD-AS graph with output gap distance visible, and prescribe the fiscal or monetary policy that closes it.
Both are output gaps, and mixing up the signs is the classic error. A recessionary (negative) gap means actual GDP is BELOW potential, so unemployment is high and you need expansionary policy. An inflationary (positive) gap means actual GDP is ABOVE potential, so unemployment is below the natural rate, inflation is rising, and you need contractionary policy. Quick check on the graph. Equilibrium left of LRAS is recessionary, right of LRAS is inflationary.
The output gap is actual real GDP minus potential (full-employment) output, per EK MEA-2.A.4.
A negative output gap is a recessionary gap, where output is below potential and unemployment is above the natural rate.
A positive output gap is an inflationary gap, where output is above potential and unemployment is below the natural rate.
On an AD-AS graph, the output gap is the horizontal distance between short-run equilibrium (AD-SRAS intersection) and the LRAS curve.
When AD and SRAS intersect exactly on LRAS, the output gap is zero and the economy is in long-run equilibrium at full employment.
Identifying the gap correctly is step one of nearly every policy FRQ, because the gap determines whether you recommend expansionary or contractionary policy.
It's the difference between actual output (real GDP) and potential output, where potential output is the full-employment level of GDP. If the economy produces $500 million but potential is $550 million, there's a $50 million negative output gap.
Not really. A positive (inflationary) gap means the economy is producing beyond its sustainable capacity, with unemployment below the natural rate and accelerating inflation. It's unsustainable, and wages will eventually rise, shifting SRAS left until output returns to potential.
A recessionary gap is negative (actual GDP below potential, unemployment above the natural rate), while an inflationary gap is positive (actual GDP above potential, unemployment below the natural rate). On the AD-AS graph, recessionary equilibrium sits left of LRAS and inflationary sits right of it.
Yes. When AD and SRAS intersect exactly on the LRAS curve, actual output equals potential output, unemployment equals the natural rate, and the economy is in long-run equilibrium with no gap.
No. The gap is zero when unemployment equals the natural rate, which is positive because frictional and structural unemployment always exist. In fact, unemployment below the natural rate (like 3% against a natural rate of 5%) signals a positive output gap.
Connect this key term to the AP exam workflow: review the course, practice questions, and check related study tools.
Review units, study guides, and course resources.
Check this vocabulary in multiple-choice context.
Apply key concepts in written AP responses.
Estimate the exam score you are working toward.
Review the highest-yield facts before practice.
Put the full course together before test day.