Answer Happy

Exercise 3. Use the Birth weight Smoking data set to answer the following question, and the dataset can be downloaded in Blackboard. Below is a description of the data: Variable Description Birth weight and Smoking 1 birthweight birth weight of infant (in grams) 2 smoker indicator equal to one if the mother smoked during pregnancy and zero, otherwise. Mother's Attributes 3 age age 4 educ years of educational attainment (more than 16 years coded as 17) 5 unmarried indicator =1 if mother is unmarried This Pregnancy 6 alcohol indicator-1 if mother drank alcohol during pregnancy 7 drinks number of drinks per week 8 triprel indicator=1 if 1 prenatal care visit in 1st trimester 9 tripre2 indicator=1 if 1' prenatal care visit in 2nd trimester 10 tripre3 indicator=1 if 1 prenatal care visit in 3 trimester 11 tripre indicator=1 if no prenatal visits 12 nprevist total number of prenatal visits 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 95% 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? Ex- plain. d. Does the coefficient on Smoker in regression (2) suffer from omitted variable bias? Ex- plain. e. Consider the coefficient on Unmarried in regression (3). i. Construct a 95% confidence interval for the coefficient. ii. Is the coefficient statistically significant? Explain. iii. Is the magnitude of the coefficient large? Explain.