中等ECON-ELAS-014
The cross elasticity of demand for tea with respect to the price of coffee is +0.5. Tea and coffee are:
A. Complements, because 0.5 is less than 1
B. Substitutes, because XED is positive✓ 答案
C. Inferior goods
D. Unrelated, because XED is not greater than 1
解說
The sign of XED classifies the relationship: positive means substitutes, negative means complements. A value below 1 does not turn substitutes into complements.