中文摘要
本文运用一个针对医疗保健部门定制的结构转型模型，研究医疗支出在时间与空间上的变异。文章回应了一个关键张力：跨国数据与时间序列数据显示，医疗支出份额随整体消费上升，表明总量收入弹性大于1；然而在各国内部，医疗支出在不同家庭收入之间却基本持平，且对石油驱动的收入冲击的准实验性支出反应呈现出与收入之间小于一比一的上升。校准模型以两种方式调和了这一张力：第一，医疗支出通过政府或保险机构在不同收入之间实现均等化。第二，在自身价格弹性的绝对值大于1的情况下，医疗保健之外的正向冲击（如石油收入冲击）会产生价格效应，从而压低医疗支出份额。我发现收入上升确实是医疗支出的主导驱动因素，而提高医疗保健部门生产率的改革将推动其支出份额上升。
Abstract
This paper studies variation in healthcare expenditures across time and space using a model of structural transformation tailored to the healthcare sector. It addresses a key tension: cross-country and time-series data show the health spending share rising with overall consumption, suggesting an aggregate income elasticity above one, yet within countries health spending is flat across household incomes, and quasi-experimental spending responses to oil-driven income shocks rise less than one-for-one with income. The calibrated model reconciles this tension in two ways: First, health spending is equalized across incomes by the government or insurers. Second, with an own-price elasticity greater than one in absolute value, positive shocks outside healthcare such as oil income shocks generate price effects that drive the health share down. I find that rising incomes are indeed the dominant driver of healthcare spending, and that reforms that raise the productivity of the healthcare sector will drive its spending share up.