Is the Life Expectancy Expected to Decline Eventually?

Despite a robust healthcare system, life expectancy in the United States is low compared to other high-income developed countries. Some of the reasons for such a trend are obesity, excessive use of drugs, alcohol consumption, and suicides. 

According to World Development Indicators, reported by the World Bank Group, in 2018, the life expectancy at birth was 78.54 years in the United States, whereas 78.89 years in the North American region and an average of 80.66 years within high-income countries. Using the same database, the life expectancy at birth for males was 76.1 years, and for females was 81.1 years in 2018. Interestingly, one trend that does not change, except in the 19th century, be it a high-income or the least developed country, is that women tend to live more than men. 

Not only did the United States fare worse compared to other developed nations, but it also witnessed a decline in its life expectancy rates from 2015 to 2017, the first time in decades since the 1918 flu pandemic. The top ten reasons for death in 2016 and 2017 – heart disease, cancer, unintentional injuries, chronic lower respiratory diseases, stroke, Alzheimer’s disease, diabetes, influenza and pneumonia, kidney disease, and suicide – accounted for 74% of the deaths in 2017. 

Social scientists and health experts have concluded similar results using various samples – gender-specific disaggregation, age-group-specific data, White versus Hispanic, uneducated versus highly educated, and so on. ‘Deaths of despair’ – a term coined by Anne Case and Angus Deaton in a research article titled Rising morbidity and mortality in midlife among white non-Hispanic Americans in the 21st century – refers to high rates of suicide, drug overdoses, and alcohol-related liver disease among working-age white men and women without four-year college degrees. The study, however, failed to factor in regional disparities and variations within the selected age-groups. A later study published in 2018 found the prevalence of declining life expectancy trend across all groups in the United States, though in varied proportions. 

In the post-pandemic world, while these causes persist, new complications among COVID-19-infected people could further decline the overall life expectancy. Though information and research on this are limited, some of the most commonly reported symptoms include fatigue, cough, arthralgia, and chest pain. Moreover, less common but serious complications such as pulmonary function abnormalities, acute kidney injury, depression, and anxiety, have been reported until now. These symptoms in young survivors, who were physically fit before contracting the virus, could lead to a declining older population. 

But do the trends of life expectancies across the world alone affect how our population changes? A series of other factors such as fertility rates, replacement rates, birth rates, mortality rates, and so on contribute to a shift in demographics. It further depends on other factors such as knowledge and usage of contraceptives, maternal health care, education, and the prevalence of social norms around childbirth, particularly in low-and-middle-income countries. 

Moreover, increases in life expectancy and other factors are an implication of better primary and secondary healthcare infrastructure, a healthier lifestyle, and other aspects such as happiness, satisfaction with life, and sound mental health, which points towards a high population growth rate. 

The world is bound to undergo a seismic demographic shift in the decades to come, as per the population projections of various demographics researchers. In one such study titled Fertility, mortality, migration, and population scenarios for 195 countries and territories from 2017 to 2100: a forecasting analysis for the Global Burden of Disease Study, the authors lay out the population scenarios in the coming decades, until 2100. The research shows that while it projects China to peak at a population of 1431·91 million persons in 2024, the estimated projection for the United States stands at 363·75 million persons in 2062.  

The limited carrying capacity of Earth could sustain an optimum population of 1.5 to 2 billion, rather than more than 7 billion people, according to Paul Ehrlich, the author of The Population Bomb. Estimates through modeling show that the population would peak at 9.73 billion people in 2064. The estimated population in the 2100 reference scenario and the 2100 SDG scenario would reach 8.7 billion and 6.2 billion people, respectively.

Fertility rates are declining well below the replacement rates due to women’s education and increased access to contraception, as expected. On the other hand, in China and India, the replacement rate exceeds the fertility rate, leading to a younger demographic. If such trends persist in the long-run, it will lead to severe socio-economic and environmental implications. A higher population means a higher consumption, leading to a higher carbon footprint and a rise in global temperatures. 

In high-income and developed countries, low birth rates would imply fewer young people to support the social security infrastructure for those who are currently aged and have a different set of financial needs. One way to solve both of these problems described is to loosen up immigration policies. While migrants from the developing South will forcefully leave their lands due to population pressures on constrained resources, the developed countries will allow entry to these migrants into their lands to support their social infrastructure for the aged. 

Only in a world where the state controls drug abuse and excessive intake of fast foods and sugary diets, technologists design innovative machinery to detect and cure chronic illnesses speedily, and medical professionals conceive advancements in the efficacy of internal medicines – would the life expectancy resist declining.