to begin, run three regressions: (1) birthweight on smoker (2) birthweight on smoker, alcohol, and nprevist (3) birthweight on smoker, alcohol, nprevist, and unmarried (a) what is the value of the estimated effect of smoking on birth weight in each of the regressions? (b) construct a confidence interval for the effect of smoking on birth weight, using each of the regressions. (c) does the coefficient on smoker in regression (1) suffer from omitted variable bias? explain. (d) does the coefficient on smoker in regression (2) suffer from omitted variable bias? explain. (e) consider the coefficient on unmarried in regression (3). i. construct a confidence interval for the coefficient. ii. is the coefficient statistically significant? explain. iii. is the magnitude of the coefficient large? explain. iv. a family advocacy group notes that the large coefficient suggests that public policies that encourage marriage will lead, on average, to healthier babies. do you agree?
