Monetary values of increasing life expectancy: sensitivity to shifts of the survival curve

个人在不同年龄死亡的风险受到政府政策的影响，包括健康、安全和环境法规。为了帮助评估新的和现有的法规是否提高了国家福利，政府的政策需要将救命和其他好处的货币价值估计与法规的成本进行比较。降低死亡风险的货币价值通常使用两种方法中的一种来估计。一种在交通运输和环境监管中常见的方法，将每年的货币收益估计为“每一统计寿命的价值”(VSL)和每年预期的“拯救的生命”数量的乘积。第二种方法在食品安全和药品监管中很常见，它将收益估计为“每一统计寿命年的价值”(VSLY)和平均预期寿命增加的乘积。由于预期寿命取决于所有未来年龄的死亡风险，因此第二种方法假定，个人将相同的货币价值分配给产生相同预期寿命增长的任何减少风险的时间路径；例如，在年轻时降低事故风险，或在年老时降低心脏病发作风险。最近的研究挑战了这一假设，研究发现，个人在降低死亡率风险的时间路径上有系统地不同的偏好；一些人更喜欢短期风险降低，另一些人更喜欢在年龄较大的时候降低风险。这项研究的目标是估计美国人口死亡率风险降低的货币价值，并描述它如何随着预期寿命的总增长和年度风险降低的时间路径而变化。这些知识应该有助于改进对某些政府政策好处的货币价值的估计，以便与其成本进行比较，并有助于其他领域的决策，如评估不那么正式的医疗保健。该项目将开发一种声明的偏好调查工具，通过互联网对代表美国成年人口的1000人或更多人进行调查，并分析结果，以确定降低死亡率风险的货币价值如何取决于预期寿命的增加和风险降低的时间路径。调查将向每个受访者提供一份说明和图表，说明他或她在接下来的几十年至100岁期间每年死亡或存活的基线机会(以年龄和性别为条件)。它还将介绍这一基线风险函数的扰动，该函数是通过仅在第一个十年降低死亡风险，并通过减去一个常量或乘以一个常量来降低未来十年的死亡风险而获得的。将对这三种扰动进行校准，以产生相同的预期寿命增长。受访者将被要求报告他们在三种扰动中每一对之间的偏好(以测试一致性)，并分别报告他们的意愿。该奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。

Individuals' risks of dying at different ages are affected by government policies including health, safety, and environmental regulations. To help evaluate whether new and existing regulations enhance national welfare, government policies require comparing estimates of the monetary value of the life-saving and other benefits with the costs of the regulations. The monetary value of reductions in mortality risk is usually estimated using one of two approaches. One approach, common in transportation and environmental regulation, estimates the annual monetary benefits as the product of a "value per statistical life" (VSL) and the expected number of "lives saved" per year. The second approach, common in food-safety and drug regulation, estimates the benefits as the product of a "value per statistical life year" (VSLY) and the average increase in life expectancy. Because life expectancy depends on mortality risk at all future ages, this second approach assumes that individuals assign the same monetary value to any time path of risk reduction that produces the same gain in life expectancy; e.g., a reduction in accident risk when young or heart-attack risk when older. This assumption is challenged by recent research that finds individuals have systematically different preferences over time paths of mortality-risk reduction; some people prefer near-term risk reductions, others prefer risk reductions at older ages. The goal of this research is to estimate the monetary value of mortality-risk reduction in the American population and to describe how it varies with the total gain in life expectancy and the time path of annual risk reductions. This knowledge should help in refining estimates of the monetary value of the benefits of certain government policies for comparison with their costs, and contribute to decision making in other domains such as health care where evaluation is less formal.The project will develop a stated-preference survey instrument, administer the survey over the internet to a sample of 1000 or more individuals representative of the adult US population, and analyze the results to determine how the monetary value of mortality-risk reduction depends on the gain in life expectancy and the time path of the risk reductions. The survey will present to each respondent a description and graphic illustrating his or her baseline annual chances of dying in or surviving each of the following decades through age 100 (conditional on age and gender). It will also present perturbations of this baseline hazard function, obtained by reducing mortality risk for only the first decade, and by reducing mortality risk in all future decades by subtracting a constant or multiplying by a constant. The three perturbations will be calibrated to produce the same increase in life expectancy. Respondents will be asked to report their preferences between each pair of the three perturbations (to test for consistency) and separately to report their willingnessThis award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.