A comprehensive AP Macroeconomics mini-lesson focused on the Fisher Effect, exploring nominal and real interest rates, expected inflation, and borrower-lender payoff shifts.
4 Part 4: AP Free-Response Style Multi-Part Question (4 pts)
Prompt: The central bank of Country X conducts expansionary monetary policy, causing the inflation rate to accelerate unexpectedly from an expected rate of 2% to an actual rate of 6%. Nominal interest rates on existing 10-year government bonds were set at 5%.
(a) Calculate the ex-ante (expected) real interest rate on the bonds when issued.
(b) Calculate the ex-post (actual) real interest rate realized on the bonds after the inflation spike.
(c) Identify whether bondholders (lenders) or the government (borrower) benefited from this monetary shock. Explain why.
AP Macroeconomics Student Practice • Check your answers with the teacher key Page 2 of 2
A. Numerical Values (2 pts • 1 pt each)
• New Nominal Interest Rate (\(i\)): 8.0% \((3\% + 5\%)\)
• New Real Interest Rate (\(r\)): 3.0% (remains unchanged)
B. Economic Explanation (2 pts)
In the long run, money is neutral. The real interest rate is determined by real factors (savings supply and investment productivity). As expected inflation rises by 3 percentage points, lenders demand a 3% higher nominal return to offset inflation, and borrowers are willing to pay 3% more because price levels rise at that same pace. Nominal rates rise 1-for-1.
4 Part 4: AP Free-Response Solutions (4 Points • 1 pt each)
AP Exam FRQ Scoring Standard
(a) Ex-Ante Real Interest Rate 1 Point
Answer: 3.0% (or +3%). Award 1 pt for stating \(r_{\text{ex-ante}} = 5\% - 2\% = 3\%\).
(b) Ex-Post Real Interest Rate 1 Point
Answer: -1.0% (or negative 1%). Award 1 pt for showing \(r_{\text{actual}} = 5\% - 6\% = -1\%\). Must explicitly show or state the negative sign.
(c) Identification & Economic Reasoning 2 Points
Identification (1 pt): State clearly that the government (borrower) benefits, while bondholders (lenders) are hurt.
Explanation (1 pt): Explain that actual inflation exceeded expected inflation (\(6\% > 2\%\)), turning the real rate negative (\(-1\%\)). The government repays fixed nominal debt with dollars worth less in real terms than anticipated, diminishing real debt burden.
AP Reader Grading Notes & Common Student Mistakes
• Missing Signs: In Part 1 Economy D, watch for students who calculate \(5 - 2 = 3\%\) instead of \(5 - (-2) = 7\%\). Deflation increases the real burden of debt!
• Incomplete FRQ Explanations: Students frequently identify the winner correctly but fail to mention real interest rate change or purchasing power in their explanation. Full credit requires explaining why the real burden dropped.
AP Macroeconomics Teacher Scoring Key • Unit 4 Page 2 of 2
