NO.PZ201512020300000202
问题如下:
2. Did Batten’s regression analyze cross-sectional or time-series data, and what was the expected value of the error term from that regression?
选项:
解释:
A is correct.
because the data are time series, and the expected value of the error term, E(Ԑ), is 0.
请问这个error term为什么是0呀