By Including Another Variable in the Regression, You Will

Multiple Choice

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.