External Costs of Obesity

描述(申请人提供)：成人肥胖是一个棘手的公共卫生问题。一份大型文献记录了美国肥胖率的上升，并衡量了相关的健康和会计成本。十多年前，沃尔夫和科尔迪茨估计，肥胖造成的医疗成本和工作场所生产率损失每年超过680亿美元。与肥胖相关的发病率和会计成本使经济学家和公共卫生从业者都倡导大力的公共干预。然而，肥胖造成的医疗成本的衡量本身并不与公众采取行动遏制肥胖是否合理的辩论息息相关。相反，最相关的是成年人不能承担的体重决定的成本(以下称为外部成本)。(潜在)补贴肥胖的一个重要机制是通过医疗保险。有一个小型的经验性文献，旨在衡量可归因于肥胖的公共医疗保险的成本。这篇文献只关注肥胖和非肥胖成年人之间的医疗支出差异，而忽略了相关的支付差异。例如，在医疗保险的情况下，这篇文献没有考虑通过税收、与肥胖相关的不同死亡率以及医疗保健支出的时间安排而产生的不同贡献。在雇主提供私人保险的情况下，文献忽略了一种可能性(由补偿工资差异理论所暗示)，即相对于较瘦的工人，覆盖范围较大的肥胖工人由于预期医疗支出较高而减少。即使对补贴进行适当的衡量，也不足以计算医疗保险造成的肥胖外部性造成的福利损失。如果补贴没有改变医保池中人的行为，那么补贴只是从瘦子到肥胖者的一次无成本转移，不会改变社会福利。关键问题是：转移到肥胖成年人身上会在多大程度上改变他们的饮食和锻炼决定的动机？外部性造成的福利损失与补贴的规模和体重决定相对于补贴的弹性成正比。我们提出了三项任务：(1)从终生角度衡量医疗保险对肥胖个人的净补贴；(2)衡量雇主提供的健康保险导致的净补贴；(3)衡量健康保险导致的补贴扭曲体重决定的程度。

DESCRIPTION (provided by applicant): Adult obesity is a thorny public health problem. A large literature documents rising obesity prevalence in the U.S., and measures the associated health and accounting costs. Over a decade ago, Wolf and Colditz measured the health care costs and lost workplace productivity due to obesity to be over $68 billion annually. The morbidity and accounting costs associated with obesity have led economists and public health practitioners alike to advocate vigorous public intervention. However, measures of medical costs due to obesity are not, in and of themselves, germane to the debate over whether public actions to curb obesity are justified. Rather, it is the costs of body weight decisions not borne by an adult making those decisions (hereafter, external costs) that are most relevant. An important mechanism by which obesity is (potentially) subsidized is through health insurance. There is a small empirical literature aimed at measuring the cost of public health insurance attributable to obesity. This literature focuses solely on health expenditure differences between obese and non-obese adults but ignores relevant payment differences. In the case of Medicare, for example, this literature does not consider differential contributions via taxes, differential obesity-related mortality, and the timing of health care expenditures. In the case of employer provided private insurance, the literature ignores the possibility (implied by the theory of compensating wage differentials) that, relative to thinner workers, covered obese workers are reduced because of their higher expected medical expenditures. Even a proper measurement of the subsidy is not enough to calculate the welfare loss from the obesity externality caused by health insurance. If the subsidy does not change the behavior of the people in a health insurance pool, then the subsidy is just a costless transfer from the thin to the obese that does not change social welfare. The key question is: to what extent do transfers to obese adults change incentives regarding their diet and exercise decisions? The welfare loss from the externality is proportional to both the size of the subsidy and the elasticity of body weight decisions with respect to the subsidy. We propose three tasks: (1) to measure the net subsidy from non-obese to obese individuals induced by Medicare from a lifetime point of view; (2) to measure the net subsidy induced by employer-provided health insurance; and (3) to measure the extent to which body weight decisions are distorted by health insurance induced subsidies.