1. Suppose we estimate the regression y = eta_0 + eta_1x_1 + eta_2x_2 + u, using 282 observations. We then conduct several hypothesis tests with significance level α = 0.05: F-test for goodness of fit, two Breusch-Pagan tests, and two White tests (using the predicted dependent variable in a cubic specification). Complete the table below (critical values, test statistics, p-values, and conclusions of each test).
| Test Type | Critical Values | Test Statistics | P-Value | Conclusion |
|-------------------------|-----------------|-----------------|---------|------------|
| F-test for goodness of fit | 3.8694 | | | |
| Breusch-Pagan (F) | 2.1 | | | |
| Breusch-Pagan (LM) | | 0.135 | | |
| White (F) | | | 0.0421 | |
| White (LM) | | | | |
2. In the model y = eta_0 + eta_1x_1 + eta_2x_2 + u, we estimate hat{eta}_1 = 4 and hat{eta}_2 = -2. Suppose that var(u_i) is decreasing with x_1. Sketch what we would expect the plot of the residuals against hat{y} to look like.
3. Suppose we estimate the regression y = eta_0 + eta_1x_1 + eta_2x_2 + u. We find hat{eta}_1 = 2.5, hat{eta}_2 = -0.73, SST = 10,000, and R^2 = 0.45. We then compute sum_{i=2}^{n} (hat{u}_i - hat{u}_{i-1})^2 = 18,425. The Durbin-Watson critical values for α = 0.05 are d_L = 0.77 and d_U = 0.82. What can we conclude about autocorrelation in this regression? Justify.