This afternoon I attended a lecture in Berkeley by Nobel prize winning economist Robert Fogel titled “Changes in the Disparities in Chronic Diseases During the Course of the Twentieth Century.” After writing most of this post I discovered a paper (PDF) of the same name that contains all of the slides presented during the lecture. Some interesting points:

Male life expectancy at age 50 from ~1900 to ~1990 increased 6.6 years (life expectancy at birth increased by decades over the same time period), while onset of disabling conditions occur roughly 10 years later in life, meaning that we not only live longer, we spend less total time in a state of ill health. To put it another way, healthspan (not a word used by Fogel) is increasing faster than lifespan, contrary to the popular fear that longer life only means more time spent bedridden. I believe the way that Fogel did put it is that decline in morbidity has paralleled and actually exceeded decline in mortality. When questioned Fogel confirmed that this is the idea he intended to convey, and added somewhat jokingly that we should not dismiss the possibility that younger people today would be healthy until they finally all drop dead together.

Drawing on the Early Indicators Project and other data Fogel stated that chronic disease in mid and late life is heavily influenced by infection and other “insults” to health in early life. He indicated data from Dutch Famine survivors may indicate that the effect may be multi-generational — the children of mothers who were themselves fetuses during the famine may be less healthy than expected. This claim seemed tentative.

Before the twentieth century human lives really fit the description of nasty, brutish, and short. Fogel cited much data from Union army recruits and pensioners. One item: in 1861, one sixth of recruits aged 16-19 were rejected for a litany of medical conditions almost unknown to today’s youth. Over half of those aged 35-39 were rejected.

Concerning the lecture’s title, Fogel said that the health of the poorest has improved far more markedly than the health of the most wealthy.

Over a similar time period the gap in average height between British elites and the average Briton shrunk from four inches to less than one.

Perhaps the most stunning figure cited concerned homelessness. In the past (I’m not certain I heard the year correctly, perhaps circa 1750) 10-20% of Europe’s population was classified as vagrant or pauper. Now, less than 0.4% of the population in wealthy countries is homeless. The stunning bit however, is Fogel’s contention as to why vagrancy was so widespread in centuries past: severe malnutrition. Large segments of the population simply didn’t get enough calories to do useful work.

Regarding increasing healthcare expenditures, Fogel made several pithy comments:

Poor people live through pain, wealthy people go to the doctor.

In poorer times people spent most of their incomes on necessities. Now we spend an increasing amount on entertainment and healthcare. Why not spend our wealth on healthcare?

Somewhat jokingly: Going to the doctor and chatting in the waiting room is a favorite activity of many elderly. It’s difficult to factor out what is entertainment and what is healthcare.

A woman once told Fogel that she had a Mercedes in her mouth — that’s how much her dental work had cost. A young person may prefer a fancy car, and older person, if they must choose, may prefer teeth, or a knee.

Improvements in health outcomes from say 1970 to 2000 are not due only to improvements in medical technology during that time, but also due to improved “pysiological capital” built up over decades (recall that health in early life heavily impacts health in later life). Future cost estimates typically completely ignore this factor.

Unfortunately, the same factor may make the problem of an aging population worse than expected in countries like China, whose current middle aged population suffered “terrible insult” in early life.

Today’s lecture was the first of a two-part series titled “Changes in the Process of Aging During the Twethieth Century.” A paper ($5 — unless you’re a subscriber or in a poor country — much like what the Creative Commons developing nations license allows) of the same name is cited here with some data. Tomorrow’s lecture on “Common Analytical Errors in Explanations for Improvements in Health and Longevity.” Supposedly both will be available online at some point.