This dissertation consists of two policy papers and one methods paper, all grounded in applied, empirical health-services research. The first two papers concern the influence of medical underwriting in the market for long-term care insurance in the U.S. The third presents a framework for evaluating provider preference as an instrumental variable in comparative effectiveness research with multiple treatments, using as an empirical demonstration a study comparing the safety of five atypical antipsychotics and their effects on chronic disease incidence. In the first paper, I estimate an empirical model of the factors on which firms make decisions to underwrite individuals for long-term care insurance, using data on the health and coverage dec...