Câu hỏi: What result is proved by the Gauss-Markov theorem?

A. That OLS gives unbiased coefficient estimates

B. That OLS gives minimum variance coefficient estimates

C. That OLS gives minimum variance coefficient estimates only among the class of linear unbiased estimators

D. That OLS ensures that the errors are distributed normally

Câu 1: Which of the following statements is correct concerning the conditions required for OLS to be a usable estimation technique?

A. The model must be linear in the parameters

B. The model must be linear in the variables

C. The model must be linear in the variables and the parameters

D. The model must be linear in the residuals

Câu 2: The value of the Durbin Watson test statistic in a regression with 4 regressors (including the constant term) estimated on 100 observations is 3.6. What might we suggest from this? 

A. The residuals are positively autocorrelated

B. The residuals are negatively autocorrelated

C. There is no autocorrelation in the residuals

D. The test statistic has fallen in the intermediate region

Câu 3: Which of the following is a correct interpretation of a “95% confidence interval” for a regression parameter?

A. We are 95% sure that the interval contains the true value of the parameter

B. We are 95% sure that our estimate of the coefficient is correct

C. We are 95% sure that the interval contains our estimate of the coefficient

D. In repeated samples, we would derive the same estimate for the coefficient 95% of the time

Câu 4: Which of the following is NOT correct with regard to the p-value attached to a test statistic?

A. p-values can only be used for two-sided tests

B. It is the marginal significance level where we would be indifferent between rejecting and not rejecting the null hypothesis

C. It is the exact significance level for the test

D. Given the p-value, we can make inferences without referring to statistical tables

Câu 5: Two researchers have identical models, data, coefficients and standard error estimates. They test the same hypothesis using a two-sided alternative, but researcher 1 uses a 5% size of test while researcher 2 uses a 10% test. Which one of the following statements is correct?

A. Researcher 2 will use a larger critical value from the t-tables

B. Researcher 2 will have a higher probability of type I error

C. Researcher 1 will be more likely to reject the null hypothesis

D. Both researchers will always reach the same conclusion

Câu 6: What is the relationship, if any, between t-distributed and F-distributed random variables?

A. A t-variate with z degrees of freedom is also an F(1, z)

B. The square of a t-variate with z degrees of freedom is also an F(1, z)

C. A t-variate with z degrees of freedom is also an F(z, 1)

D. There is no relationship between the two distributions