The data in WAGE2.RAW on working men was used to estimate the following models. The estimates of the two simplified versions of these models are Model 1: lwage = 5.973 + 0.0598educ N=935 and R = 0.0974 (0.0813) (0.0059) Model 2: lwage = 5.496 + 0.07486educ + 0.0153exper + 0.0133tenure (0.1105) (0.0065) N=935 and R = 0.1551 (0.0033) (0.0025) where, educ is years of schooling, lwage is the log of wages, exper represents years of work experience, age is the age in years, age2 is the age squared, tenure is the years with current employer, and IQ is the IQ score. a) Discuss the interpretation of the coefficient on educ in Model 1. [5 Marks] b) Interpret the given R in Model 1. [5 Marks] c) Is either tenure or exper individually significant in Model 2 at the 5% level against a two-sided alternative? Explicitly show your work. [5 Marks] d) Are exper and tenure jointly significant in Model 2 at the 5% level? Justify your answer. [5 Marks] e) The researchers suspect that the first two models above suffer from the omitted variable bias. If that's the case, what are the consequences? Explain. Would you be able to comment on the direction of the bias? Given your answer, what would you suggest that the researchers do next? [10 Marks] In the next step, researchers estimated the following model.