1.statement 3 错误的原因是因为wider是基于成本（答案中）的考虑，而不是基于风险（题干中）的考虑么，2.那为什么

问题如下：

Which of West’s statements regarding rebalancing ranges is least likely correct?

选项：

A.

Statement 1.

B.

Statement 2.

C.Statement 3.

解释：

Correct Answer: C

Statement 3 is incorrect. Rebalancing ranges for non-US developed equity should be wider than US equity under the cost-benefit (not proportional range) because it has higher transaction costs. Rebalancing ranges under the proportional range approach are defined as +/– 600 basis points for all asset classes in this example and are computed as follows.

Rebalancing ranges for bonds under the proportional range approach:

20% × (1 + 600 bps) = 20% × 1.06 = 21.2%

20% × (1 – 600 bps) = 20% × 0.94 = 18.8%

Hypothetical Rebalancing Ranges under Three Different Approaches