In April 2020, the United Nations University World Institute for Development Economics Research released a working paper estimating that the economic consequences of the COVID-19 pandemic could drive up to half a billion people around the world into poverty, which would be the first increase in global poverty since 1990. This reflects something paradoxical about the COVID-19 moment: on one hand, it felt like a time of unprecedented disruption. But on the other hand, that an increase in global poverty could be seen as such a profound anomaly speaks to the fact that when the pandemic appeared, in many respects the world had never been better off or healthier. In a number of key areas—life expectancy, rises in education and literacy, reductions in preventable diseases such as HIV/AIDS— the 21st century was, and is, a more favorable time to be alive than any other point in recorded history.
Right now, it can be easy to overlook our historical successes. On any given day, we are likelier to hear a news anchor report that 37 people were killed in a terrorist attack than we are to hear her say that global poverty continued to decline, as it has for the last 30 years. Yet news of the decline in global poverty is far more representative of the trajectory of life for most people in the 21st century than news of a terrorist attack is. Seeing this requires us to look beyond the moment, when our feelings about our health are clouded by the soupy fog of COVID-19, and view the sweep of history, seeing how the decades leading up to now have ushered in unparalleled progress.
Seeing the scale of the progress we have made in building a healthier world raises questions about the drivers of this success. A good way to find the answers is by looking at the last century. How our past shaped our present holds lessons for how we might shape our future, and how to continue the positive upward trend in human health.
So how does life in the first year of the 20th century compare to now? In some respects, discussing 1900 and discussing today is like talking about two different worlds. But among the most striking measures of progress is the rise in life expectancy. In the United States, a child born in 1900 could on average expect to live to about age 47. Today, that child can expect to live to about age 79.
Why this difference? The answer most people would give is simple: better medicine. It is a compelling answer, but it is only partially true. One of the reasons life expectancy is among the most useful measures of overall population health is because no single factor accounts for it. Life expectancy is the product of the context in which our lives unfold. So while it is true that the last century saw remarkable achievements in medicine—from polio vaccination to, more recently, advanced treatments for HIV/AIDS—medicine alone cannot account for such a significant, multi-decade gain in life expectancy. Something deeper is at work.
Let us, then, compare the life of someone born in 1900 with the life of someone born today. In the years leading up to 1900, the U.S. industrialized and urbanized in the wake of the Civil War. Concurrent with these trends came waves of immigrants hoping to settle in this land of rapidly growing opportunity. They came for better lives, yet for many the opportunity of America was interwoven with hardship.