问一道题：NO.PZ2018091701000018

问题如下：

If investor’s income and wealth substantially increase, which of the following statement is most likely correct?

选项：

Investor’s intertemporal rate of substitution will be larger than 1.

Investor is less willing to buy risky assets.

Investor’s marginal utility of consumption is decreasing.

解释：

C is correct.

考点：跨期替代率（inter-temporal rate of substitution）和消费的边际效用（marginal utility of consumption）

解析：投资者财富增加，消费的边际效用 是减小的。?这是因为随着财富的增加，投资者本身最基本的需求已经被满足了，那么投资者每多花1元钱所带来的效用与之前满足需求所带来的效用相比，满足感就会有所减少。