(a) Explain how a universal healthcare system would likely cause a greater amount of efficient turnover.
(b) Defined-benefit retirement plans promise a fixed amount of retirement income to workers, but in order to receive benefits workers must be vested in the plan which usually requires working at the firm for 10 or 15 years. In contrast, a defined-contribution retirement plan specifies a fixed amount of money the firm contributes each pay period to a worker's retirement fund which the worker then largely controls and can access even if she changes jobs. Do defined-benefit or defined-contribution retirement plans allow for more efficient turnover? How is the social security system in the United States like a defined-benefit plan? How is it like a defined-contribution plan?
(c) When federal workers in Washington D.C. move jobs from one federal agency to another, the worker keeps her same health insurance and retirement benefits. In order to quantify the degree to which ease of transfer of benefits affects turnover, two groups of new economists Ph.D.s who accept a job in Washington D.C. are observed. The first group contains US citizens. The second group contains non-US residents who eventually received permanent resident status after 3 years of work experience. By law, several government agencies cannot hire non-residents. Among the group of US citizens, 42 percent changed jobs within the first 3 years of work while 33 percent changed jobs during their fourth to sixth years of work. Among the group of non-US residents, 17 percent changed jobs in the 3 years before becoming a resident while 29 percent changed jobs in the 3 years after becoming a US resident. Provide a difference-in-differences estimator of the effect of being a US resident/citizen in Washington D.C. for Ph.D. economists.