中等ECON-INFL-001
A household took a fixed-rate mortgage before an unexpected rise in the CPI. Who gains in real terms?
A. The lender, because the real value of the repayments rises
B. The borrower, because the real burden of the fixed nominal repayment falls✓ 答案
C. Both equally, because the nominal rate already included the unexpected rise
D. Neither, because a fixed basket means the CPI cannot change the real burden
解說
Unanticipated inflation cuts the purchasing power of a fixed nominal repayment, so the borrower gains and the lender loses. If the rise had been expected, the nominal rate could have been set higher. The CPI basket being fixed is a measurement issue, not a reason the real burden is unchanged.