January 2, 2008
What’s Your Consumption Factor?
By JARED DIAMOND
TO mathematicians, 32 is an interesting number: it’s 2 raised to the fifth power, 2 times 2 times 2 times 2 times
2. To economists, 32 is even more special, because it measures the difference in lifestyles between the first world and the
developing world. The average rates at which people consume resources like oil and metals, and produce wastes like
plastics and greenhouse gases, are about 32 times higher in North America, Western Europe, Japan and Australia than
they are in the developing world. That factor of 32 has big consequences.
To understand them, consider our concern with world population. Today, there are more than 6.5 billion people,
and that number may grow to around 9 billion within this half-century. Several decades ago, many people considered
rising population to be the main challenge facing humanity. Now we realize that it matters only insofar as people consume
If most of the world’s 6.5 billion people were in cold storage and not metabolizing or consuming, they would
create no resource problem. What really matters is total world consumption, the sum of all local consumptions, which is
the product of local population times the local per capita consumption rate.
The estimated one billion people who live in developed countries have a relative per capita consumption rate of 32. Most
of the world’s other 5.5 billion people constitute the developing world, with relative per capita consumption rates below 32,
mostly down toward 1.
The population especially of the developing world is growing, and some people remain fixated on this. They
note that populations of countries like Kenya are growing rapidly, and they say that’s a big problem. Yes, it is a problem
for Kenya’s more than 30 million people, but it’s not a burden on the whole world, because Kenyans consume so little.
(Their relative per capita rate is 1.) A real problem for the world is that each of us 300 million Americans consumes as
much as 32 Kenyans. With 10 times the population, the United States consumes 320 times more resources than Kenya
People in the third world are aware of this difference in per capita consumption, although most of them couldn’t
specify that it’s by a factor of 32. When they believe their chances of catching up to be hopeless, they sometimes get
frustrated and angry, and some become terrorists, or tolerate or support terrorists. Since Sept. 11, 2001, it has become