Nearly 40 years ago, the demographer Samuel Preston (1975) wrote about changing patterns of life expectancy and income around the world. That paper set the agenda for thinking about global health and global wealth. Its key figure remains useful for describing past and current progress in health and wealth – where we have been and where we are going – as well as for looking at the great health catastrophes of the second half of the twentieth century.
Figure 1 updates Preston’s graph using data from 1960 and 2010. It is taken from Chapter 1 of my book The Great Escape: health, wealth, and the origins of inequality, and illustrates one of the book’s central themes, that the world is a better place than it used to be, albeit with big setbacks, and that progress opens up vast inequalities. The inequalities, depending on circumstance, can promote further growth, or they can stifle growth, and they frequently pose serious ethical issues.
Figure 1. Health and wealth around the world
The figure plots life expectancy at birth (for both sexes together) against per capita GDP in price-adjusted international dollars. Each point is a country, shown as a circle whose area is proportional to population; the lighter circles are for 1960, and the darker circles for 2010. The arrow points in the direction of progress, where both per capita incomes and life expectancy increase over time. The 2010 line is above the 1960 line so that, for a typical country, life expectancy has increased by more than would have been expected given a movement along the 1960 line. Preston suggested that movement along the curve was the effect of income on health, while the upward movement of the line could perhaps be attributed to technical progress.
Death 'ages' as we move along each curve; this is the epidemiological transition. In the poorest countries, parents still live with the agony of watching their children die from long-conquered maladies like pneumonia, diarrhea, or vaccine preventable diseases like measles. In the rich countries, where disease has moved out of the bowels of children and into the arteries of the elderly, death comes from chronic diseases – heart disease and cancer – and comes to the old, not to the young. The aging of death recapitulates what happened in history, though poor countries today have achieved comparable health at much lower levels of per capita income than was the case in the rich countries in the past. When I was born in Edinburgh in 1945, life expectancy in Scotland was lower than it is in India today; when my father was born in the Yorkshire coalfield in 1918, child mortality in England was higher than it is in sub-Saharan Africa today.
Progress and horrors
Progress has been repeatedly interrupted by horrors, not all of which are safely locked up in a historical museum. The Figure shows the huge increase in life expectancy in China between 1960 and 2010, most of which happened, not slowly over time, but immediately after 1960. In fact, this is not a story of progress, but of the unwinding of the disaster of the great Chinese famine. Mao’s demented attempt to catch up with rich countries in a few years, to assume leadership in the Communist world, and to preserve his own political position at home, led him to ignore the mounting evidence that millions were dying. Eventually, perhaps 30 million people died, Yang (2013). This is far from the first time in history that toxic politics has brought human catastrophe. It is sometimes hard to see the benefits that good policies bring, but the Great Leap Forward is a spectacular example of what bad policies and bad politics can do.
The figure also shows a smattering of countries well below the 2010 line, the largest of which is the dark circle for South Africa. This is the HIV/ADIS pandemic that, for the affected countries in Africa, undid the hard won growth of life expectancy that had taken place between 1950 and 1990. Such disease-based disasters remind us that we cannot safely assume that the age of plagues can never return.
While the relationship between health and wealth is the natural focus of the figure, the univariate distributions of health and wealth document immense global inequality. National life spans range from 30 years to more than 80 years, while per capita GDP ranges from less than $300 to the more than $40,000. And because of the positive correlation across countries, inequalities in income come with matching inequalities in health; those who get a bad draw in income also get a bad draw in health. That these inequalities are familiar can blind us to their enormity, and that they, themselves, are the result of past progress. After 1750, when Britain, followed by north-western Europe, began to see sustained economic growth in per capita incomes together with increases in life expectancy, these countries pulled away from the rest of the world, creating gaps that have never closed. Global inequalities, in both health and wealth, are largely the residual afterglow of the first escapes from deprivation and early death.
What of the future?
Today, there is concern about falling economic growth at the technological frontier, a decline that has been accompanied by and is perhaps contributing to greater national inequality. But, in the rich countries of the world, declining growth has not brought a deceleration in the pace of mortality decline. Driven by lower smoking rates – especially among men – and by progress in (mostly preventative) treatment of cardiovascular disease, mortality rates have fallen rapidly for half a century, with new drugs and new knowledge rapidly moving from one rich country to another. Patterns of mortality decline, which once were idiosyncratic from one country to another, are now closely coordinated. The prevention of cardiovascular disease – for example by antihypertensive drugs – costs very little so there is great potential for its extension to middle-income countries, where infectious diseases are no longer the main killers. Today, there is also real progress against some cancers so that, with luck, the next fifty years will see as much reduction in cancer mortality as has been seen in the last fifty years in cardiovascular mortality. Unfortunately, cancer treatments are expensive, and will pose difficult trade-offs between health and wealth; we may have to choose between better health and greater material prosperity.
The greatest inequalities in the world today – and the most ethically troubling – are those between rich and poor countries. African babies routinely die from diseases that we have known how to prevent or cure for the best part of a century. And three-quarters of a billion people live on less than a(n international) dollar per person per day, itself an almost unimaginably low standard. For many people, the obvious way to close these gaps and to meet the moral commitment is through foreign aid from rich to poor. If we calculate how much every poor person falls below an international dollar per day, and multiply by the number of poor, the total is less than $1 a day for each adult American, and half of that if Western Europeans were to pile in too. Just why this beguiling calculation is irrelevant, and why aid is harming people in those countries whose governments are largely funded by foreign aid, is the topic of the final – and most controversial – chapter of The Great Escape.
Deaton, Angus (2013), The Great Escape: health, wealth, and the origins of inequality, Princeton, NJ and Oxford, Princeton University Press.
Preston, Samuel (1975), “The changing relation between mortality and economic development,” Population Studies, 29:2, 231–48.
Yang Jisheng (2012), Tombstone: the great Chinese famine, 1958–62, Farrar, Straus and Giroux.