이 알바는 경험도 쌓고 돈도 벌 수 있어서 이석일조예요.
A. 对
B. 错
By including another variable in the regression, you will
A. decrease the regression R2 if that variable is important.
B. eliminate the possibility of omitted variable bias from excluding that variable.
C. look at the t-statistic of the coefficient of that variable and include the variable only if the coefficient is statistically significant at the 1% level.
D. decrease the variance of the estimator of the coefficients of interest.
Errors-in-variables bias
A. is present when the probability limit of the OLS estimator is given by ![]()
.
B. arises when an independent variable is measured imprecisely.
C. arises when the dependent variable is measured imprecisely.
D. always occurs in economics since economic data is never precisely measured.
Sample selection bias
A. occurs when a selection process influences the availability of data and that process is related to the dependent variable.
B. is only important for finite sample results.
C. results in the OLS estimator being biased, although it is still consistent.
D. is more important for nonlinear least squares estimation than for OLS.
微信支付 
支付宝支付