Bryan Caplan  

The Simon-Ehrlich Rematch: Was There Any Wheat Amongst the Chaff?

Income Distribution Reality... Is Ehrlich the Least Hansonian...

You've probably heard about the famous Simon-Ehrlich wager, but did you know the Ehrlich asked for a rematch? Paul Ehrlich and Steve Schneider proposed to bet $1000 on each on the following:

1. The three years 2002-2004 will on average be warmer than 1992-1994. (Rapid climate change associated with global warming could pose a major threat of increasing droughts and floods.)

2. There will be more carbon dioxide in the atmosphere in 2004 than in 1994. (Carbon dioxide is the most important greenhouse gas driving global warming.)

3. There will be more nitrous oxide in the atmosphere in 2004 than in 1994. (Nitrous oxide is another greenhouse gas that is increasing due to human disruption of the nitrogen cycle.)

4. The concentration of ozone in the lower atmosphere (the troposphere) will be greater in 2004 than in 1994. (Tropospheric ozone is a component of smog that has important deleterious effects on human health and crop production.)

5. Emissions of the air pollutant sulfur dioxide in Asia will be significantly greater in 2004 than in 1994. (Sulfur dioxide in the atmosphere becomes sulfuric acid, the principal component of acid rain, and it is associated with direct damage to human health, forests, and crops.)

6. There will be less fertile cropland per person in 2004 than in 1994. (Much of Earth's best farmland is being paved over, but even if it weren't, population growth will reduce per-capita acreage.)

7. There will be less agricultural soil per person in 2004 than in 1994. (Erosion virtually everywhere far exceeds rates of soil generation.)

8. There will be on average less rice and wheat grown per person in 2002-2004 than in 1992-1994. (Rice and wheat are the two most important crops consumed by people.)

9. In developing nations there will be less firewood available per person in 2004 than in 1994. (More than a billion people today depend on fuelwood to meet their energy needs.)

10. The remaining area of virgin tropical moist forests will be significantly smaller in 2004 than in 1994. (Those forests are the repositories of some of humanity's most precious living resources, including the basis for many modern pharmaceuticals worldwide.)

11. The oceanic fisheries harvest per person will continue its downward trend and thus in 2004 will be smaller than in 1994. (Overfishing, ocean pollution, and coastal wetlands destruction will continue to take their toll.)

12. There will be fewer plant and animal species still extant in 2004 than in 1994. (Other organisms are the working parts of humanity's life support systems.)

13. More people will die of AIDS in 2004 than did in 1994 (as the disease takes its toll of already infected individuals, continues to spread in Africa, and takes off in Asia.)

14. Between 1994 and 2004, sperm counts of human males will continue to decline and reproductive disorders will continue to increase. (Over the past fifty years, sperm counts worldwide may have declined as much as 40 percent. Paul and Steve bet this trend will continue due to the widespread use and environmental persistence of hormone-disrupting synthetic organic chemical compounds.)

15. The gap in wealth between the richest 10 percent of humanity and the poorest 10 percent will be greater in 2004 than in 1994.

Simon objected, quite properly in my view, that many of these bets have little or nothing to do with human welfare. (E.g., why is #15 about inequality instead of the per-capita income of the poorest 10%?! Why is #6 about cropland instead of food production? Why is #8 about rice and wheat instead of calories?)

The parentheticals try to make this connection, of course, but by my lights, few of them succeed. Still, some of these 15 bets seem a lot closer to human welfare than others. So: Which of these 15 bets should Simon have been willing to take?

Comments and Sharing

COMMENTS (7 to date)
Garrett Schmitt writes:

Simon should probably only have gone for #13, if any of them.

His prescience in the first bet was seeing that there was an unsustainable general boom in commodity prices in the 1970s which made his bet against the doomsayers a sure thing. With #13 he could probably tell from publicly available statistics whether he would have been taking a bet in the run up to a "boom" in AIDS deaths or not.

Furthermore, death from illness is a valid detractor to human welfare, and what progress there has been in treatments for AIDS supports his theme of optimism even if it may not have won that particular bet.

Snark writes:

Looks like Simon could have earned money betting on #8 (World Rice and Wheat supply/demand schedule).

Garrett Schmitt writes:

UN-FAO crop production statistics
US Census mid-year world population
Data from both sites accessed today.
Kilograms per capita figures are my calculation:
Year Rice Wheat
1992 97.16882618 103.9272953
1993 95.98983133 102.2563994
1994 96.23718674 94.10996019
2002 91.4604801 92.37520943
2003 92.78677309 88.99117763
2004 95.32035507 99.39874339

'92-'94 average per capita production was 96.5kg and 100.1kg, rice and wheat respectively
'02-'04 average per capita production was 93.2kg and 93.6kg, rice and wheat respectively

Bother, I suppose he would have lost that one, too. For reference, the FAO also generates some indices on per capita food production which say humanity is doing better, but a bet is a bet.

Snark writes:


Thanks for crunching the numbers. I haphazardly read #8 and supplied data disregarding per capita totals. By your calculations, Simon (technically speaking) loses. Implicit in the bet, however, was the premise that demand would exceed supply, resulting in a production shortfall. That definitely wasn't the case, which is perhaps one reason why Simon chose not to accept the terms.

Dave writes:

#11 if you include aquaculture

Charlie writes:

The whole point of the Simon-Ehrlich bet was about prices. The problem with carbon dioxide, ozone, and other pollutants is that there is no price for people to respond to. Same goes for fisheries and biodiversity. Hence, 1-5, 11, and 12 aren't really in the spirit of the original bet.

Kolohe writes:

In addition to what Charlie wrote above, most of these suffer from severe selection bias, and some actually indicate a rise in living standards.

Take #14. Back in the day, when you didn't have kids, you were 'barren' even if you were 'upright in the sight of god.' It's only been in the past few decades where we've understood the science, that it could be the failing of either of the two that it takes to tango, and only in the past decade where such tests and subsequent treatments are 'affordable'.

And who's going to go for testing, the couple that needs to buy a bigger minivan for their brood, or the couple that's worried someone is shooting blanks?

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