高階econ-u02-d06
The price elasticity of supply of fresh vegetables tends to be low over a single day because:
A. Supply cannot expand quickly in such a short time period✓ 答案
B. Demand for vegetables is always perfectly elastic
C. A price ceiling forces PES to be zero
D. Vegetables have no opportunity cost
解說
PES depends heavily on the time period available. In a very short run, land, greenhouse space and crop cycles are fixed, so a small price rise cannot bring much extra supply. Over months, PES is much higher.