In this exercise you will study health insurance, health status, and employment using a random sample of more than 8000 workers in the United States surveyed in 1996. The data are available on the textbook Web site svwvv spearsonhighered.comistock_watson in the file Insurances A detailed description is given in Insurance_Description, available on the Web site.

a. Are the self-employed less likely to have health insurance than wage earners? If so, is the difference large in a real-world sense? Is the difference statistically significant?

b. The self-employed might systematically differ from wage earners in their age. education, and so forth. After you control for these other factors, are the self-employed less likely to have health insurance?

c. How does health insurance status vary with age? Are older workers more likely to have health insurance? Less likely?

d. Is the effect of self-employment on insurance status different for older workers than it is for younger workers?

e. It has been argued that the self-employed are less likely to be insured, but despite this, they are just as healthy as wage-earners. Is this right? Does the argument hold up for young workers? For older workers? Are there potential two-way causality problems that might under-mine the internal validity of this kind of statistical analysis?