The LRPC (long-run Phillips curve) is a vertical line at the natural rate of unemployment showing that in the long run there is no trade-off between inflation and unemployment, because the economy returns to full employment at any inflation rate (AP Macro Topic 5.2, EK MOD-3.A.3).
LRPC stands for the long-run Phillips curve, and it's the vertical line in the Phillips curve model. It sits at the natural rate of unemployment (NRU) and stays vertical no matter what inflation does. The message is simple. In the long run, you can have 2% inflation or 10% inflation, but unemployment ends up at the natural rate either way. There's no permanent trade-off between inflation and unemployment (EK MOD-3.A.3).
Contrast that with the SRPC, the downward-sloping short-run Phillips curve, which does show a trade-off because wages and expectations are sticky in the short run. Long-run equilibrium happens where the SRPC crosses the LRPC (EK MOD-3.A.4). The economy is always somewhere on its SRPC, and the LRPC tells you where it must eventually land. If you're to the left of the LRPC, the economy is in an inflationary gap. To the right, it's in a recessionary gap. Think of the LRPC as the Phillips-curve twin of the LRAS curve from the AD-AS model. Both are vertical, both are anchored at full employment, and both say the same thing in different units.
The LRPC lives in Unit 5: Long-Run Consequences of Stabilization Policies, Topic 5.2. It directly supports learning objective AP Macro 5.2.A (define the SRPC and LRPC using graphs), 5.2.B (explain short-run and long-run equilibrium in the Phillips curve model), and 5.2.C (explain how unemployment and inflation respond in the short run versus the long run). The LRPC is the punchline of Unit 5's big idea. Expansionary policy can push unemployment below the natural rate for a while, but expectations adjust, the SRPC shifts, and the economy slides back to the LRPC with higher inflation and nothing to show for it on unemployment. That's the whole argument against trying to permanently buy lower unemployment with inflation, and it's why this graph shows up constantly on the exam.
Keep studying AP® Macroeconomics Unit 5
Short-Run Phillips Curve (SRPC) (Unit 5)
The SRPC and LRPC are a package deal. Demand shocks move you along the SRPC, supply shocks and changing inflation expectations shift the SRPC, and the LRPC is the anchor everything returns to. Long-run equilibrium is literally the point where the two curves intersect (EK MOD-3.A.4).
Natural Rate of Unemployment and Full Employment (Unit 2)
The LRPC is parked exactly at the NRU, which is frictional plus structural unemployment from Unit 2. If something changes the NRU itself, like job training programs or unemployment benefit reform, the whole LRPC shifts (EK MOD-3.B.3). Cyclical unemployment never moves the LRPC.
Long-Run Aggregate Supply (LRAS) (Unit 3)
The LRPC is the LRAS curve translated into Phillips-curve language. LRAS is vertical at full-employment output; the LRPC is vertical at full-employment unemployment. A gap on one graph shows up as a matching gap on the other, and AP questions love asking you to move between the two models.
Long-Run Self-Adjustment (Unit 3)
The mechanism that pulls the economy back to the LRPC is the same wage adjustment story from Topic 3.6. In an inflationary gap, nominal wages rise, the SRPC shifts right (higher expected inflation), and the economy ends up back on the LRPC at a higher inflation rate.
The Phillips curve is a graphing workhorse on the AP Macro exam. FRQs regularly give you an unemployment rate above or below a stated natural rate and ask you to draw a correctly labeled Phillips curve graph. The 2017 SAQ (actual unemployment 7%, NRU 5%) and 2019 SAQ (unemployment 6%, NRU 4%, expected inflation 3%) both required plotting a point on the SRPC relative to a vertical LRPC at the natural rate. The 2025 FRQ started the economy in long-run equilibrium, meaning at the SRPC-LRPC intersection. On MCQs, expect stems asking why the LRPC is vertical (adjusting inflation expectations), what shifts the LRPC (only changes to the NRU, like job training or benefit reform), and how the curves behave when expected inflation rises (SRPC shifts up along a fixed LRPC). Your jobs are concrete. Draw the LRPC vertical at the NRU, label axes as inflation and unemployment, place the short-run point correctly, and explain the return to long-run equilibrium through shifting expectations.
The SRPC slopes downward and shows a real short-run trade-off, so lower unemployment comes with higher inflation along it. The LRPC is vertical and shows no trade-off at all. The clean rule for what moves what: demand shocks move you along the SRPC, supply shocks and changed inflation expectations shift the SRPC, and only changes in the natural rate of unemployment shift the LRPC. If a question involves monetary or fiscal policy, the LRPC does not move.
The LRPC is vertical at the natural rate of unemployment, showing there is no long-run trade-off between inflation and unemployment.
Long-run equilibrium occurs where the SRPC intersects the LRPC; points left of the LRPC are inflationary gaps and points right of it are recessionary gaps.
Monetary and fiscal policy cannot shift the LRPC; only changes in the natural rate of unemployment, such as job training programs or unemployment benefit reforms, move it.
The LRPC is vertical because inflation expectations adjust over time, shifting the SRPC until unemployment returns to the natural rate.
The LRPC is the Phillips-curve counterpart of the LRAS curve, since both are vertical at full employment.
On FRQs, always draw the LRPC as a vertical line at the stated natural rate and plot the economy's current point on the SRPC relative to it.
The LRPC is the long-run Phillips curve, a vertical line at the natural rate of unemployment. It shows that in the long run there is no trade-off between inflation and unemployment, which is essential knowledge MOD-3.A.3 in Topic 5.2.
Because inflation expectations adjust over time. If policy pushes unemployment below the natural rate, workers and firms come to expect higher inflation, the SRPC shifts up, and unemployment returns to the natural rate at a higher inflation rate. Any inflation rate is consistent with the same natural rate of unemployment.
No. Demand-side policy only moves the economy along the SRPC in the short run. The LRPC shifts only when the natural rate of unemployment changes, for example through job training programs or unemployment benefit reforms that change frictional and structural unemployment.
The SRPC is downward sloping and shows a short-run trade-off between inflation and unemployment, while the LRPC is vertical at the natural rate and shows no trade-off. Demand shocks move you along the SRPC, supply shocks shift the SRPC, and only changes in the natural rate shift the LRPC.
They say the same thing on different graphs. LRAS is vertical at full-employment output in the AD-AS model, and the LRPC is vertical at the natural rate of unemployment in the Phillips curve model. An inflationary gap on one graph corresponds to a point left of the LRPC on the other.
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.