1. Which of the following is false? a. The ordering of cross-sectional data set does not matter for econometric analysis. b. Pooled cross-section data set has both cross-sectional and time series features. b. The ordering in the cross section of a panel data set does not matter. d. The cross-sectional units followed in a panel data do not have to be the same. 2. Which of the following is true? a. A variable has a causal effect on another variable if both variables increase or decrease simultaneously b. The notion of 'ceteris paribus' plays an important role in causal analysis. c. Difficulty in inferring causality disappears when studying data at fairly high levels of aggregation. d. The problem of inferring causality arises if experimental data is used for analysis. 3. Consider the following table which gives data on egg production and egg prices in 5 states in the unic data set is it? State Year Eggs Produced (millions) Price per dozen (cents) California 1990 7472 63.4 Michigan 1990 1406 58.0 California 1991 7444 58.4 Florida 1991 2537 57.2 Illinois 1991 809 70.5 a. Panel data b. Pooled cross-sectional data c. Cross-sectional data d. Time series data 4. Which of the following is not true for the sampling variance of the OLS estimator ? a. As the variability in x, increases, the variance of , increases. b. The larger the error variance, the larger is the sampling variance of the OLS estimator. c. More variance in the unobservables affecting the dependent variable makes it more difficult to precise d. A larger sample size results in a smaller sampling variance of the OLS estimator. 5. The Gauss-Markov theorem will not hold if a. the error term has the same variance given any values of the explanatory variables b. the error term has an expected value of zero given any values of the independent variables c. the independent variables have exact linear relationships among them d. the regression model relies on the method of random sampling for collection of data