The empirical findings on the relationship between gross domestic product (GDP) and health expenditure are diverse. The influence of income levels on this causal relationship is unclear. This study examines if the direction of causality and income elasticity of health expenditure varies with income level. It uses the 1995–2014 panel data of 161 countries divided into four income groups. Unit root, cointegration and causality tests were employed to examine the relationship between GDP and health expenditure. Impulse-response functions and forecast-error variance decomposition tests were conducted to measure the responsiveness of health expenditure to changes in GDP. Finally, the common correlated effects mean group method was used to examine the income elasticity of health expenditure. Findings show that no long-term cointegration exists, and the growth in health expenditure and GDP across income levels has a different causal relationship when cross-sectional dependence in the panel is accounted for. About 43% of the variation in global health expenditure growth can be explained by economic growth. Income shocks affect health expenditure of high-income countries more than lower-income countries. Lastly, the income elasticity of health expenditure is less than one for all income levels. Therefore, healthcare is a necessity. In comparison with markets, governments have greater obligation to provide essential health care services. Such results have noticeable policy implications, especially for low-income countries where GDP growth does not cause increased health expenditure.

中文翻译：

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卫生支出和国内生产总值：按收入水平进行因果分析。

关于国内生产总值（GDP）和卫生支出之间关系的实证研究结果是多种多样的。收入水平对这种因果关系的影响尚不清楚。这项研究检验了卫生支出的因果关系和收入弹性的方向是否随收入水平而变化。它使用了161个国家（分为四个收入组）的1995-2014年面板数据。单位根，协整和因果关系检验用于检验GDP与卫生支出之间的关系。进行了冲动响应函数和预测误差方差分解测试，以测量卫生支出对GDP变化的响应度。最后，采用共同相关效应均值分组法检验卫生支出的收入弹性。研究结果表明，不存在长期的协整关系，并且考虑到面板中的横断面依赖性时，卫生支出和GDP在不同收入水平之间的增长具有不同的因果关系。全球卫生支出增长的大约43％的变化可以用经济增长来解释。收入冲击对高收入国家的卫生支出的影响大于对低收入国家的影响。最后，在所有收入水平上，卫生支出的收入弹性都小于1。因此，医疗保健是必要的。与市场相比，政府有更大的义务提供基本的医疗保健服务。这种结果具有明显的政策影响，特别是对于GDP增长不会引起医疗支出增加的低收入国家。