Use the data in TRAFFIC2 for this exercise. (i) Run an OLS regression of prcfat on a linear time trend, monthly dummy variables, and the variables wkends, unem, spdlaw, and beltlaw. Test the errors for AR(1) serial correlation using the regression in equation (12.20). Does it make sense to use the test that assumes strict exogeneity of the regressors?
(ii) Obtain serial correlation–and heteroskedasticity-robust standard errors for the coefficients on spdlaw and beltlaw, using four lags in the Newey-West estimator. How does this affect the statistical significance of the two policy variables?
(iii) Now, estimate the model using iterative Prais-Winsten and compare the estimates with the OLS estimates. Are there important changes in the policy variable coefficients or their statistical significance?

When paul o’neill joined alcoa as ceo, he set a , that there would be zero workplace accidents. a lot of people in the organization thought this was impossible given how dangerous some aluminum-manufacturing jobs are, but alcoa’s safety record improved tremendously. as the board of governors of the american red cross considers planning, one option is to make strategic plans and then direct managers to align tactical and operational plans accordingly. another option is to have planning specialists managers across the organization make their own plans. why might this organization’s executives opt for the latter approach? check all that apply. (a) the environment is a dynamic one, and department and frontline managers can come up with more responsive plans than can central leadership. (b)resources will be better coordinated across the organization in support of the overall strategy.(c) senior leadership will have more control over the organization’s direction. (d)when managers come up with their own plans, they are likely to be more committed to following through on them.