Effects of health expenditure, death rate, and infant mortality rate on life expectancy: A case study of the United States

Understanding the factors that influence life expectancy (LEXP) is crucial for promoting economic development, as a nation's prosperity depends on the health of its population. Various socioeconomic, nutritional, lifestyle, genetic, and environmental factors can significantly impact a nation's health and longevity. Our study investigates these drivers of LEXP, focusing on the United States as a case study. Using quarterly data from 2000 to 2022, we examined the relationship between LEXP and multiple determinants, including environmental degradation, income levels, inflation dynamics, educational attainment, birth and death rates, health expenditure patterns, urbanization trends, and infant mortality rates. Employing advanced analytical methodologies, we accounted for the nonlinear nature of the time series data by utilizing approaches such as quantile-on-quantile Kernel Regression Least Squares and quantile-on-quantile Granger causality. The study revealed that factors such as inflation rate, rapid urbanization, high birth rates, CO2 emissions, death rates, and infant mortality negatively affect LEXP. On the other hand, higher income levels, educational attainment, food production, and health expenditure positively influence LEXP. Based on these findings, we have proposed significant policy recommendations.