高階econ-u06-d05
An oil price surge raises firms' production costs. In the short run this typically:
A. Shifts SRAS left, so the price level rises while output falls✓ 答案
B. Shifts AD right and raises both price and output
C. Leaves SRAS unchanged because only nominal costs move
D. Shifts AD left with no effect on prices
解說
Higher input costs shift short-run aggregate supply left. The result is a cost-push mix of higher prices and lower output, sometimes called stagflation, which monetary policy finds hard to offset.