NO.PZ202207040100000605
问题如下：
The portfolio method suggested by Stapleton to replicate the MSCI EAFE Index is best described as:选项：
A.optimization. B.stratified sampling. C.a blended approach.解释：
Solution
B is correct. The portfolio method that Stapleton is describing is stratified sampling. In equity indexing, stratified sampling methods are most frequently used when the portfolio manager wants to track indexes that have a large number of constituents or when dealing with a relatively low level of assets under management. In stratified sampling, the portfolio manager holds a limited sample of the index constituents arranged in distinct strata or subgroupings. Arranged correctly, the various strata will be mutually exclusive and also exhaustive and should closely match the characteristics and performance of the index.
A is incorrect. Optimization typically involves maximizing a desirable characteristic or minimizing an undesirable characteristic, subject to one or more constraints.
C is incorrect. An indexed portfolio can be managed using a blended approach consisting of full replication for more liquid issues and stratified sampling or optimization for less liquid issues.
中文解析：
本题考查的是组合构建方法的选择。我们需要分析三种可能的投资方法，并选择最合适的。
选项A：最优化的方法。最优化通常用于在一定约束下，通过数学模型来最大化或最小化某个特定目标，比如最大化预期回报或最小化风险。它的核心思想是通过优化权重分配来实现目标。然而，Stapleton建议的策略是选择一个具有代表性的指数子集，而不是进行优化计算，因此选项A不正确。
选项B：分层抽样法。该方法通常用于指数成分多且资产管理规模较小的情况。基金经理会选择一个有限的样本，并将这些证券分为不同的“层”或子群体，每个层代表指数的一个部分。这些层次是互斥的，并且应该全面覆盖整个指数的特征，从而在不持有所有成分的情况下，尽量复制指数的表现和风险特征。因此，最符合描述的是分层抽样法，因为它能在低资产规模下通过有限的样本复制指数的特征。正确答案是B。
选项C：混合方法。混合方法通常结合了全复制策略与分层抽样或优化策略，用于处理流动性差的证券。但在此题中，Stapleton并未提到同时使用这几种方法，因此选项C不适用。
从题干中哪句话判断的？为什么不选A？