基礎econ-u02-d02
For a normal good, the income elasticity of demand is:
A. Positive, because demand rises as consumer income rises✓ 答案
B. Negative, because demand falls as income rises
C. Always zero, because income is not a demand factor
D. Always greater than 1 for every normal good
解說
A normal good is defined by YED > 0. An inferior good has YED < 0, where demand falls as income rises. A luxury has YED > 1.