Mid Term Flashcards
The average of the OLS fitted values for any sample is always zero
False
When one includes an irrelevant independent variable in a regression, we call it “over controlling.”
False
If we were to change the units of measurement for one of the independent variables, the coefficient estimates for all independent variables would change.
False
If we run a regression in Stata and obtain a p-value equal to .06, we would reject the null hypothesis that the coefficient is equal to zero at the 5 percent level, but would fail to reject that null at the 10 percent level.
False
Multicollinearity refers to the situation where the independent variables are highly correlated. Multicollinearity does not cause the OLS estimator to be biased, but it does generally increase the standard errors.
True
If an estimator is consistent, then as the size of the random sample increases the estimator moves towards the true population parameter value.
True
The zero conditional mean assumption implies that ui = 0 for all i regardless of the value of xi.
False
We do not need the normality of the error term assumption to perform valid statistical inference if the other multiple linear regression model assumptions hold and we have a large sample.
True
Omitting an independent variable that is correlated with the dependent variable from an OLS regression always causes the estimated coefficients on the included independent variables to be biased.
False
A confidence interval for a prediction is always at least as small or smaller than the corresponding prediction interval.
True
One of the most important differences between an applied regression analysis course from the Statistics Department and an econometrics course from the Economics Department is the degree to which the course focuses on estimation bias caused by endogenous variables.
True
The central limit theorem states that the sample mean of a variable, when it is standardized (by the population standard deviation), has a standard normal distribution, even if the variable itself is not normally distributed.
True
Under assumption SLR.1 - SLR.4, the OLS estimates equal the true population parameters.
False
A violation of the zero conditional mean assumption would cause the OLS estimator to be biased.
True
Over specifying a model (by adding irrelevant control variables) would cause the OLS estimator to be biased.
False
The sum of the squared residuals (SSR) is equal to the difference between the total sum of squares (SST) and the explained sum of squares (SSE).
True
A sample correlation coefficient of 0.95 between the regressor of interest and another regressor in the model would cause the OLS estimator to be biased.
False
The reason OLS is commonly used is because it is the most computationally efficient unbiased linear estimator.
False