GRAD 6102/8102: Categorical Outcomes Assignment #4 October 19, 2023 Your friend, who is a public health expert, is conducting research on STD prevention. You want to analyze the 2018 GSS data to help her figure out how the number of sexual partners varies by gender and education. In the 2018 GSS data, the variable nummen is the number of male sex partners the respondent has had since age 18, and numwomen is the number of female sex partners since 18. Delete all cases where either variable is missing or greater than 700. This should reduce your sample size to 1,267. Now add the two variables to create a single variable, numpartners, for the total number of sex partners. This is your dependent variable. Your independent variables are sex, age, race, and educ. Discard cases with missing values for any of these variables. Your final sample size should be 1,266. Use this sample to complete the following tasks: Check and report the descriptive statistics for numpartners, age, and educ. Check and report the frequency distributions for sex and race. Estimate a Poisson model with numpartners as the dependent variable. Include all independent variables. This is Model 1. Interpret your findings for sex and educ. Does this model have an over-dispersion problem? Which statistic/test do you look at? Estimate a Negative Binomial model using the same variables. This is Model 2. Report your findings for sex and educ. How do they compare to those from Model 1? Which model do you prefer, Model 1 or Model 2? Construct a new variable by subtracting 17.5 from age. This is the time duration for which sex partners are counted. Include its natural log in the Negative Binomial model and drop age. This is Model 3. [We subtract 17.5 instead of 18 from age because respondents whose age is listed as 18 are somewhere between 18 and 19, with an average around 18.5; those whose age is listed as 19 are between 19 and 20; and so on.] Report your findings for sex and educ. How do they compare to those from Model 2? Calculate the predicted number of sex partners for a 35-year old white man with 16 years of education. Discuss your finding for the duration variable (logged).