NO.PZ201512300100000301
问题如下：
1. The inclusion of index returns prior to 2001 would be expected to:
选项：
A.bias the historical equity risk premium estimate upwards.
B.bias the historical equity risk premium estimate downwards.
C.have no effect on the historical equity risk premium estimate.
解释：
A is correct.
The backfilling of index returns using companies that have survived to the index construction date is expected to introduce a positive survivorship bias into returns.
老师，我对这句话没有完全理解：
“An equity index is established in 2001 for a country that has relatively recently established a market economy. The index vendor constructed returns for the five years prior to 2001 based on the initial group of companies constituting the index in 2001.”
这句话的意思是说，该指数是从2001年开始构建的，但是如果用构建这些指数的公司（the initial group of companies）来估计2001年之前5年的指数，那么将会导致指数偏高（因为这些公司是经过5年依然留下来的好公司），我的理解对吗？
谢谢老师了
