1. Identify the feature of panel data that offers an advantage over cross sectional data and explain how the analyst can exploit that advantage.
2. Briefly distinguish between correlation and causation. Use an example to support your answer.
3. Define independence between two random variables. If X and Y are independent, then Cov(X,Y) = 0. Why is the converse false? Support your answer by providing a counterexample to the converse.
4. What does the acronym "iid" mean and how does it relate to sampling? Why is it critically important to an econometric analysis to convincingly demonstrate the random nature of the data used?
5. Correlation overcomes a fundamental limitation of covariance and conditional expectation overcomes a fundamental limitation of correlation. Identify these limitations.
6. Distinguish between an estimator and an estimate. Identify three desirable properties of estimators.
7. Interpret the following statement: A recent poll indicates that popular support for the mayor is 47.5% with a margin of error of +/- 3.5 percentage points 19 times out of 20.