替代效果的問題 - 經濟

來源:參考書題庫

科目:個經

問題:Suppose a consumer has preferences between two goods that are perfect
substitutes.Can you change prices in such a way that the entire demand
response is due to income effect?


我的想法:

不是說對於完美替代而言，只會有替代效果，而不會有所得效果不是嗎?
(圖解可知)
可是答案給的是會有所得效果耶

為什麼會這樣?

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