The Phillips Curve
Help Questions
AP Macroeconomics › The Phillips Curve
Based on the short-run Phillips Curve shown, the economy moves from point $A$ to point $B$ due to a decrease in aggregate demand. Which change is illustrated in the short run?
Inflation increases and unemployment increases because the short-run Phillips Curve shifts right.
Inflation and unemployment both return immediately to the natural rate because the long run begins instantly.
Inflation increases and unemployment decreases as the economy moves along the short-run Phillips Curve.
Inflation decreases and unemployment increases as the economy moves along the short-run Phillips Curve.
Inflation decreases and unemployment decreases because the short-run Phillips Curve shifts left.
Explanation
The Phillips Curve shows an inverse relationship between inflation and unemployment in the short run, represented by the downward-sloping SRPC. When aggregate demand decreases, the economy moves down and to the right along the existing SRPC from point A to point B. This movement shows falling inflation (as reduced demand lowers price pressures) and rising unemployment (as firms lay off workers due to lower sales). A common error is thinking demand changes shift the curve, but they cause movements along it. To analyze Phillips Curve questions correctly, distinguish between movements along curves (demand changes) and shifts of curves (supply shocks or expectation changes).
Based on the Phillips Curve shown, which statement correctly describes the long run relationship between inflation and unemployment given the vertical $LRPC$ at the natural rate of unemployment $u_n$?
In the long run, lower unemployment requires permanently higher inflation along the LRPC.
In the long run, inflation must fall when unemployment returns to $u_n$.
In the long run, the SRPC is vertical, so inflation cannot change.
In the long run, the LRPC slopes downward because expectations are fixed.
In the long run, there is no stable tradeoff because unemployment returns to $u_n$.
Explanation
The Phillips Curve captures the inflation-unemployment relationship. Short-run SRPC shows a downward slope with tradeoffs, but long-run LRPC is vertical at the natural rate, meaning no permanent tradeoff. The graph's vertical LRPC at u_n indicates that in the long run, unemployment returns to the natural rate regardless of inflation levels. Attempts to lower unemployment below u_n lead to accelerating inflation without lasting gains. Misconception: believing in a stable long-run tradeoff, but expectations ensure return to u_n. Strategy: consider expectations and time horizon; long-run focus here highlights no tradeoff.
Based on the short-run Phillips Curve shown, the economy moves from point A to point B after a contractionary monetary policy reduces aggregate demand, with inflation expectations unchanged. Which change is illustrated in the short run?
Inflation decreases and unemployment increases because the economy moves down along the SRPC.
Inflation decreases and unemployment decreases because the SRPC shifts rightward.
Inflation and unemployment remain unchanged because the LRPC is vertical.
Inflation increases and unemployment increases because the economy moves up along the SRPC.
Inflation increases and unemployment decreases because the SRPC shifts leftward.
Explanation
The Phillips Curve links inflation to unemployment. In the short run, the SRPC slopes downward, allowing tradeoffs from demand changes, while the long-run LRPC is vertical with no tradeoff. The graph shows movement from A to B along the SRPC, reflecting contractionary policy reducing demand, thus lowering inflation but raising unemployment. Expectations remain unchanged in this scenario. A misconception is that such tradeoffs are stable permanently, yet they diminish over time. Strategy: check expectations and time horizon; short-run with fixed expectations confirms movement down the curve.
Based on the short-run Phillips Curve shown, the economy moves from point $A$ to point $B$ after an increase in aggregate demand. Which of the following best describes the change in inflation and unemployment in the short run?
Inflation decreases and unemployment increases because the short-run Phillips Curve shifts right.
Inflation increases and unemployment increases because the short-run Phillips Curve shifts left.
Inflation increases and unemployment decreases as the economy moves along the short-run Phillips Curve.
Inflation and unemployment both remain unchanged because there is no tradeoff in the short run.
Inflation decreases and unemployment decreases as the economy moves along the short-run Phillips Curve.
Explanation
The Phillips Curve shows the inverse relationship between inflation and unemployment in the short run. When aggregate demand increases, the economy moves up and to the left along the short-run Phillips Curve (SRPC), from point A to point B. This movement represents higher inflation and lower unemployment, as increased demand pushes prices up while firms hire more workers to meet demand. A common misconception is thinking this tradeoff is permanent, but it only exists in the short run before expectations adjust. To analyze Phillips Curve movements, always check whether you're moving along a curve (demand changes) or shifting the curve (supply shocks or expectation changes).
Based on the Phillips Curve shown, the long-run Phillips Curve (LRPC) is vertical at $u_n=5%$. If the economy is currently at point $B$ with unemployment below $u_n$, then after wages and prices fully adjust, which outcome is most consistent with the long run?
Unemployment returns to $5%$ and inflation returns to its initial level because expectations never change.
Unemployment remains below $5%$ and inflation rises permanently because of a stable long-run tradeoff.
Unemployment rises above $5%$ and inflation rises because the long-run Phillips Curve slopes downward.
Unemployment returns to $5%$ and inflation rises relative to the initial long-run equilibrium.
Unemployment remains below $5%$ and inflation falls because the economy moves down the LRPC.
Explanation
The Phillips Curve model features a vertical long-run Phillips Curve (LRPC) at the natural unemployment rate, indicating no permanent inflation-unemployment tradeoff. When the economy is at point B with unemployment below 5% (the natural rate), it cannot sustain this position indefinitely. As workers realize inflation is higher than expected, they demand wage increases, shifting the SRPC rightward until the economy reaches a new equilibrium on the LRPC at 5% unemployment. The final inflation rate will be higher than initially because expectations have adjusted upward. The misconception of a permanent tradeoff ignores that the LRPC is vertical—in the long run, unemployment always returns to its natural rate.
Based on the short-run Phillips Curve shown, the economy moves from point $A$ to point $B$. The central bank states that the change was caused by contractionary monetary policy that reduced aggregate demand. In the short run, which interpretation matches the movement shown?
Inflation increases and unemployment increases because the short-run Phillips Curve shifts right.
Inflation decreases and unemployment increases as the economy moves along the short-run Phillips Curve.
Inflation increases and unemployment decreases as the economy moves along the short-run Phillips Curve.
Inflation and unemployment are unchanged because monetary policy affects only the long run.
Inflation decreases and unemployment decreases because the short-run Phillips Curve shifts left.
Explanation
The Phillips Curve demonstrates the short-run inverse relationship between inflation and unemployment, with monetary policy affecting aggregate demand. Contractionary monetary policy reduces aggregate demand by raising interest rates, decreasing investment and consumption. This causes the economy to move down and to the right along the SRPC from point A to point B, resulting in lower inflation (reduced demand pressure) and higher unemployment (firms reduce output and employment). A common misconception is thinking monetary policy shifts the Phillips Curve, but it causes movement along the existing curve. Remember: monetary and fiscal policies that change aggregate demand cause movements along the SRPC, not shifts of it.
Based on the short-run Phillips Curve shown, the economy moves from point A to point B after a demand-side expansion (for example, increased government spending) with inflation expectations unchanged. Which change in inflation and unemployment is illustrated in the short run?
Inflation and unemployment both remain unchanged because the long run has no tradeoff.
Inflation increases and unemployment increases because the SRPC shifts right.
Inflation increases and unemployment decreases because the economy moves up along the SRPC.
Inflation decreases and unemployment decreases because the curve shifts left.
Inflation decreases and unemployment increases because the economy moves down along the SRPC.
Explanation
The Phillips Curve illustrates the relationship between inflation and unemployment in an economy. In the short run, the Short-Run Phillips Curve (SRPC) is downward-sloping, showing an inverse relationship where lower unemployment comes with higher inflation, often due to demand changes. In contrast, the Long-Run Phillips Curve (LRPC) is vertical, indicating no long-term tradeoff as unemployment returns to the natural rate. Referring to the graph, moving from point A to point B along the SRPC represents an increase in aggregate demand, such as from government spending, leading to higher inflation and lower unemployment without shifting the curve. A common misconception is assuming this tradeoff is stable long-term, but expectations adjust over time, eroding the tradeoff. A transferable strategy is to check inflation expectations and the time horizon: here, unchanged expectations confirm a short-run movement along the curve.
Based on the Phillips Curve shown, the economy is in the short run and moves from point A to point B along the same $SRPC$. Which scenario is most consistent with the movement shown?
A decrease in aggregate demand causes inflation to rise and unemployment to fall.
A decrease in long-run potential output shifts the LRPC left, lowering unemployment.
An increase in aggregate demand causes inflation to rise and unemployment to fall.
A negative supply shock shifts the SRPC right, raising inflation and unemployment.
A fall in expected inflation shifts the SRPC right, raising inflation and unemployment.
Explanation
The Phillips Curve represents the relationship between inflation rates and unemployment levels. In the short run, the SRPC slopes downward, enabling tradeoffs from aggregate demand shifts, whereas the long-run LRPC is vertical, eliminating sustained tradeoffs. The graph illustrates movement from A to B along the same SRPC, consistent with rising aggregate demand causing higher inflation and lower unemployment. This occurs without shifts in expectations or supply. People often misconceive a stable long-term tradeoff, but it fades as expectations adjust. A useful strategy is examining expectations and time frame: here, short-run demand increase with fixed expectations explains the movement along the curve.
Based on the Phillips Curve shown, the economy is in the short run and experiences a rightward shift from $SRPC_1$ to $SRPC_2$. Which combination of inflation and unemployment outcomes is consistent with this shift, holding aggregate demand constant?
Lower inflation and lower unemployment at the new short-run equilibrium.
Lower inflation and higher unemployment at the new short-run equilibrium.
Higher inflation and higher unemployment at the new short-run equilibrium.
No change in inflation or unemployment because the long run has no tradeoff.
Higher inflation and lower unemployment at the new short-run equilibrium.
Explanation
The Phillips Curve models the tradeoff between inflation and unemployment. Short-run SRPC is downward-sloping for temporary effects, while long-run LRPC is vertical, offering no sustained tradeoff. The graph shows a rightward shift from SRPC1 to SRPC2, leading to higher inflation and higher unemployment at the new equilibrium with constant demand. This could result from negative supply shocks or rising expectations. Common misconception: assuming permanent stable tradeoffs, ignoring shifts. Strategy: examine expectations and time horizon; short-run shift here implies worsened outcomes holding demand steady.
Based on the Phillips Curve shown, the economy moves from point $A$ to point $B$ following a negative supply shock (such as a large increase in oil prices). In the short run, which outcome is illustrated?
Inflation falls and unemployment rises because the economy moves up along the short-run Phillips Curve.
Inflation and unemployment are unchanged because the long-run Phillips Curve is downward sloping.
Inflation rises and unemployment falls because the economy moves down along the short-run Phillips Curve.
Inflation rises and unemployment rises because the short-run Phillips Curve shifts right.
Inflation falls and unemployment falls because the short-run Phillips Curve shifts left.
Explanation
The Phillips Curve demonstrates the short-run tradeoff between inflation and unemployment, but supply shocks create a different pattern. A negative supply shock like rising oil prices increases production costs, shifting the SRPC rightward from point A to point B. This creates stagflation—both higher inflation and higher unemployment simultaneously, breaking the usual inverse relationship. Students often assume all economic changes involve tradeoffs, but supply shocks worsen both variables. To identify supply shock effects on the Phillips Curve, look for movements where both inflation and unemployment increase (negative shock) or decrease (positive shock) together.