Get the data file \"CHARITY.DTA\" on LMS under the STATA DATA folder This assignment is based on the data set in \"CHARITY.dta\". To examine what influence individuals' decisions on donations, the linear regression model respond = 0 + 1 resplast + 2 avggift + 3 propresp + 4 mailsyear +u is used. For hypothesis-testing questions, please always present hypotheses, test statistic and its distribution under the null, decision rule and conclusion. a) What type of model is this? Why? What is the meaning of 1? (1 Mark) b) Suppose that MLR.1-4 hold for the model when all variables are correctly measured. Further suppose that respond is measured with error: respond = respond* + e (i.e., observed = actual + error). Would the OLS estimators of 's still be unbiased and consistent? why? (1 Mark) c) Suppose that MLR.1-4 hold for the model when all variables are correctly measured. Further suppose that one regressor, mailsyear, is measured with an additive error and the error is uncorrelated with the actual mailsyear*. How would the OLS estimator of 4 be affected by the measurement error? why? (1 Mark) d) Estimate the model, using OLS, and interpret the estimate of 4. Find robust standard errors and compare these with the usual OLS standard errors. (1 Mark) e) Test for the presence of heteroskedasticity, using the Breusch-Pagan LM test and White F-test. Explain the steps. Compare outcome of these tests and comment on robustness of your findings. (2 Marks) f) Suppose that MLR.1-4 hold for the model. Find the expression for Var(u|all regressors). (1 Mark) g) Given your answer to f), how would you use weighted least squares (WLS) to estimate the model? What would be the weights for the WLS? Practically, what may prevent you from implementing the WLS? (2 Marks) h) Test for possible model misspecifications, using the RESET. What does your conclusion