Why the Number of Feet Matters A recent feature on population in
the Economist discusses economic challenges when a nation’s
population falls. In this feature, “How to deal with a falling
population”, 28 July 2007, the Economist tries to minimize
concerns about world population by saying that we are “hardly
near the point of [resource] exhaustion”. The Economist received
a flood of letters insisting that rising world population and
resource depletion are indeed serious problems. So many comments
were sent in that the Economist published a follow-up piece,
Population and its discontents: Lighten the footprint but keep
the feet. This too highlighted deep misunderstandings about the
relationship between population and humanity’s demand on our
biosphere, and in particular, confusing population growth rates
and population size. Quite simply, our ecological demand is the
product of 1) the number of people times 2) per-capita demand
(consumption) times 3) the efficiency of production. Each of
these factors contribut