To estimate a multiple regression model, we need to include linear terms and an interaction term. The final version of the model will include variables that are significant and align with corporate finance knowledge.
a. To estimate a multiple regression model using the given data, we can use the variables return on average equity (X1), annual dividend rate (X2), and an interaction term involving X1 and X2. The multiple regression equation can be written as:
Y = β0 + β1X1 + β2X2 + β3(X1X2)
Where Y is the price per share of electric utility stocks, X1 is the return on average equity, X2 is the annual dividend rate, and X1X2 is the interaction term.
By estimating the coefficients β0, β1, β2, and β3, we can determine the relationship between the explanatory variables and the stock price.
b. To determine which of the three explanatory variables (X1, X2, and X1X2) should be included in a final version of the regression model, we need to assess their statistical significance and practical relevance.
Statistical significance can be evaluated by performing hypothesis tests for each coefficient. If a coefficient is statistically significant, it means that it has a significant impact on the dependent variable (stock price). On the other hand, if a coefficient is not statistically significant, it suggests that it may not be necessary to include that variable in the model.
Practical relevance, on the other hand, requires considering the knowledge of corporate finance. For example, if X1 and X2 are known to be important factors in determining stock prices, it would make sense to include them in the model. Additionally, if the interaction term X1X2 captures a meaningful relationship between X1 and X2, it should also be included.
By analyzing the estimated coefficients, p-values, and considering the knowledge of corporate finance, we can determine which explanatory variables should be included in the final regression model.