Introduction to Econometrics 3rd Edition by James Stock, Mark Watson

تمرين 14

A committee on improving undergraduate teaching at your college needs your help before reporting to the dean. The committee seeks your advice, as an econometric expert, about whether your college should take physical appearance into account when hiring teaching faculty. (This is legal as long as doing so is blind to race, religion, age, and gender.) You do not have time to collect your own data, so you must base your recommendations on the analysis of the data set TeachingRatings described in Empirical Exercise that has served as the basis for several empirical exercises in Part II of the text. Based on your analysis of these data, what is your advice Justify your advice based on a careful and complete assessment of the internal and external validity of the regressions that you carried out to answer the empirical exercises using these data in earlier chapters.
Exercise
Suppose that a random sample of 200 twenty-year-old men is selected from a population and that these men's height and weight are recorded. A regression of weight on height yields

where Weight is measured in pounds and Height is measured in inches.
a. What is the regression's weight prediction for someone who is 70 in. tall 65 in. tall 74 in. tall
b. A man has a late growth spurt and grows 1.5 in. over the course of a year. What is the regression's prediction for the increase hi this man's weight
c. Suppose that instead of measuring weight and height in pounds and inches these variables are measured in centimeters and kilograms. What are the regression estimates from this new centimeter-kilogram regression (Give all results, estimated coefficients, R 2 , and SER.