NO.PZ2022122601000041
问题如下：
A new consumer credit mechanism was being tested on a small scale using a smartphone application to pay for items instead of the traditional credit card. The application had proved successful in the use of microloans in developing countries and was now being applied to a much broader consumer base. The new challenge for Li's team is to develop a model for the expected return for these new consumer credit companies, which are called ―"smart credit" companies because they combine the consumer credit industry and what had traditionally been considered the telecommunications industry.
Although smart credit company returns data are sparse, a five-year monthly equally weighted index called the "Smart Credit Index" (SCI) was created from the existing companies’returns data. The number of companies in the index at a given time varies because of firms failing and also merging over time.
The SCI data most likely exhibits which type of bias?
选项：
A.Data-mining
B.Survivorship C.Time-period解释：
Correct Answer: B
The SCI data is an index that is not composed of the same number of firms each period because of firm failures and combinations through time, which is indicative of a survivorship bias.
中文解析：
SCI数据是一个指数，它不是由每个时期相同数量的公司组成，因为随着时间的推移，公司倒闭和合并，这表明存在生存偏差。
The number of companies in the index at a given time varies because of firms failing and also merging over time.
这句是否指，index中包含了failing的公司？
