NO.PZ2018122801000072
问题如下:
The proper selection of factors to include in an ordinary least squares estimation is critical to the accuracy of the result. When does omitted variable bias occur?
选项:
A.Omitted variable bias occurs when the omitted variable is correlated with the included regressor and is a determinant of the dependent variable.
B.Omitted variable bias occurs when the omitted variable is correlated with the included regressor but is not a determinant of the dependent variable.
C.Omitted variable bias occurs when the omitted variable is independent of the included regressor and is a determinant of the dependent variable.
D.Omitted variable bias occurs when the omitted variable is independent of the included regressor but is not a determinant of the dependent variable.
解释:
A is correct.
考点Omit Variable
解析Omitted variable bias occurs when a model improperly omits one or more variables that are critical determinants of the dependent variable and are correlated with one or more of the other included independent variables. Omitted variable bias results in an over-or under-estimation of the regression parameters.
这道题我错选了C选项,因为不太理解“omitted variable is correlated with the included regressor”,我选的是independent。