Friday, April 19, 2019

The unexpected down side of better public health

kw: book reviews, nonfiction, public health, demographics

First impression: Thomas J. Bollyky should have employed a co-author. His book Plagues and the Paradox of Progress is very difficult reading, not just because of the emotional weight of the subject, but because he writes for PhD-level readers (I subjected certain paragraphs to the Gunning Fog Index algorithm, which yielded numbers of 19 and greater. That's worse than most legal contracts!). Yet the subject is very important. So much so, that I read through it anyway.

A thousand years ago, life expectancy at birth, almost anywhere on Earth, was in the range of 25-30. This was still true just 150-200 years ago, but that was beginning to change. Nonetheless, this picture of a cemetery in Missouri, where my ancestors are buried, is instructive (Payne is a family name). When I took this picture I inadvertently recorded the basic demographic fact about life prior to 1880 in America: half of these tombstones are half-size, indicating children five years of age or younger. The larger tombstones commemorate people who typically lived into their fifties to eighties. Even a millennium ago, if a child survived at least five years, remaining (average) life expectancy could exceed sixty years.

The advances in public health have been very uneven. As described in the book, the countries of today's "first world", mainly the U.S., Europe and Japan, began making changes to infrastructure and health practice that reduced infant and youth mortality, and the spread of infectious diseases in general, more than 200 years ago. Progress was slow and not always steady. But the one big effect of all this was a gradual "younging" of the adult population. More children survived childhood and grew into young workers. Because the changes occurred over decades or even a century or more, employment for this glut of young workers grew at a rate that employed most of them. Much of that employment was in the growing cities, which grew into many of the mega-cities of today.

That's oversimplified, but the major and obvious effect of better public health is a demographic shift. If a country or region has a growing employment base, which typically means growing cities and more manufacturing, the economic benefits multiply. A major problem with citification is that crowded conditions foster the spread of infectious diseases, so for a generation or two (or three), the burden of disease shifted from early childhood to the working years. Many of the major cities of the Western world grew only because in-migration exceeded the appalling death rate from cholera, tuberculosis, and other diseases of crowding. Further public health measures, such as quarantine, and later, effective medications (beginning in the early 1900's), reduced the toll of plagues and other infections. Thus the "first world" has average life expectancy at birth in the range of 80 years!

A second demographic effect has been that families got smaller. A couple didn't need to have five or more children to ensure that a few would survive to become their parents' "retirement plan". Of course, some couples just like to have a lot of kids anyway; a neighbor of ours has 18 siblings, all from the same mother and father! But few Western families have more than two or three children, a great many have only one, and among Millennials, the trend is toward having none.

The "third world" (is there a "second world"?) has had it different. And worse. Rich nations began helping poor nations with medical and financial aid around a century ago. So the life expectancy in most countries exceeds 70 years (160 out of 223). I looked up a few in the CIA World FactBook: Albania, 79y; Bangladesh, 74y; Thailand, 75y; Libya, 77. However, other places still lag: Angola, 61y; Ethiopia, 60y; Laos, 65y; Botswana, 64y. The lowest life expectancies are to be found in sub-Saharan Africa, ranging down to the mid-fifties.

The book describes what has happened. Death rates among infants and children, and generally from infectious disease, have been dropping. As a consequence, there is a glut of younger people trying to make a living. The mass migrations, for primarily economic reasons, that began in the 1700's and 1800's, are accelerating as the poor countries of the world struggle to (and usually fail to!) employ their teeming millions.

The last chapter has a "what do we do about it?" message. The answer: much more...but what? So far, there is a little hope here and a little there. Malaria and AIDS and cholera and TB get all the press. Even though there is still a ways to go, progress to date has led to a demographic crisis that is being mainly ignored by the various bodies that have been addressing the diseases. Nobody has broad-based plans to address the resulting glut of young workers.

Well, that just presents the problem. Who will solve it? We're at risk of many good trends of the past few centuries being reversed. At this point I'd usually say, "Read the book." But many won't be able to, unless they are ready to cope with prose that you need 19 years of education to read without difficulty. I hope someone takes this book and its deficiencies as a challenge to write a better one, a more accessible one.

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