Marika Ilona Cabral
Published: 2011
Total Pages: 290
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This dissertation consists of four distinct essays. In an essay entitled "Claim Timing and Ex Post Adverse Selection: Evidence from Dental 'Insurance, ' " I explore the impact of strategic timing on insurance market allocations. If people can delay a claim just long enough to buy more insurance coverage in anticipation of it, severe adverse selection may result, and in extreme cases, this can lead to the complete unraveling of an insurance market. I study these forces by analyzing dental treatments and insurance, with the goal of understanding insurance in the market for dental care and also revealing lessons that apply to insurance markets more broadly. Using rich claim-level data from a large firm, my analysis reveals that the strategic delay of treatment and the associated adverse selection may be an important factor in explaining why so few people have dental coverage in the US and why typical dental "insurance" contracts provide so little insurance. More generally, my results suggest that insurance products without contract features designed to limit coverage for strategically delayed costs (e.g., open-enrollment periods, pricing pre-existing conditions) may generate unraveling. An essay entitled "The Hated Property Tax: Salience, Tax Rates, and Tax Revolts" (with Caroline Hoxby), explores the relationship between the salience of the property tax and observed property tax rates. We hypothesize that high salience explains the unpopularity of the property tax, the level of the property tax, and prevalence of property tax revolts. To identify variation in the salience of the property tax over local jurisdictions and over time, we exploit conditionally random variation in tax escrow, a method of paying the property tax that makes it much less salient. We find that areas in which the property tax is less salient are areas in which property taxes are higher and property tax revolts are less likely to occur. In an essay entitled "Private Coverage and Public Costs: Identifying the Effect of Private Supplemental Insurance on Medicare Spending" (with Neale Mahoney), we explore the impact of private supplemental insurance on Medicare spending. Private supplemental insurance to "fill the gaps" of Medicare, known as Medigap, is very popular. We estimate the impact of this supplemental insurance on total medical spending using an instrumental variables strategy that leverages discontinuities in Medigap premiums at state boundaries. Our estimates suggest that Medigap increases medical spending by 57 percent---or about 40 percent more than previous estimates suggest. Back-of-the-envelope calculations indicate that a 20 percent tax on premiums would generate combined revenue and savings of 6.2 percent of Medicare baseline costs. An essay entitled "The Effect of Insurance Coverage on Preventive Care" (with Mark Cullen), explores the effect of insurance coverage on preventive care utilization. Using health insurance claims data from a large company, this paper examines the implementation of an insurance benefit design which differentially increased the marginal price of curative care (non-preventive care) while decreasing the marginal price of prevention. We examine the effect of the differential price change on the use of preventive procedures. We reveal evidence consistent with an important negative cross-price effect; that is, increases in the price of curative care can depress preventive care utilization.
