From: carnes@sparky.eecs.umich.edu (Richard Carnes)
Subject: Re: Malthus was just ahead of his time
Organization: University of Michigan EECS Dept., Ann Arbor
Date: Sun, 5 Apr 1992 20:53:21 GMT

dietz@cs.rochester.edu (Paul Dietz) writes:

>This contradicts the figures I have.  There *was* some slowdown in the
>mid to late 80s (helped in part by the "payment in kind" policy which
>reduced grain surpluses in the US), but growth has overall been strong
>since.  In particular, world rice production increased 1.8%/year from
>1987 to 1991, maize production increased 5.2%/year from 88-89 to
>90-91, and wheat production 4.3%/year from 87-88 to 90-91 (Source: CRB
>Commodity Report, 1991.)

These figures don't really contradict Lester Brown's claim, which was
that per-capita world grain production has decreased (but not
monotonically) from 1984 to 1990 or -91.  In any case, it is difficult
to draw firm conclusions from short-term data, since the productivity
figures jump about a good deal from year to year owing to weather and
whatnot.  After the monotonic dive in grain production from 1984 (~345
kg/person) to 1988 (~300 kg/person) (USDA figures, cited by Brown),
the 90s will tell an interesting tale.  I know of no scientific reason
to conclude that per-capita food production will increase
"inexorably", as you put it.  Brown puts it this way:

  In many ways, changes in the amount of grain that can be *sustainably*
  produced per person may be the best single indicator of success in the
  battle to save the planet.  If an upward trend can be restored in the
  years immediately ahead -- one that reduces hunger and malnutrition --
  it will be a clear sign of victory.  If, on the other hand, per capita
  grain supplies continue to decline, leading the world into an era of
  food scarcity, rising food prices, and political instability, it will
  be a sure sign that the battle is being lost. [STATE OF THE WORLD
  1990, p. 12; emphasis added]

BTW, this does not sound like a prophecy of doom.

> >Note that Japan's rice yield per unit area, despite domestic price
> >supports at four times the world market and despite the comparative
> >literacy and scientific orientation of Japanese farmers, increased an
> >average of only 0.9% per year in the 1970s and 80s, while the
> >projected world population increase in the 90s is 1.7% per year.
>
>This is a wonderful example of a common fallacy -- that because the
>market has not caused something to happen (in this case, Japanese
>farmers to increase output) that thing must be impossible.  It could
>very well be that Japan's farmers would find increased production
>unprofitable at this time.  They are certainly *not* the world's low
>cost producers.

Nobody claimed that it was *impossible* for Japanese farmers to have
increased per-hectare rice yields faster than they did.  If they found
further increases in productivity to be unprofitable, might not this
have something to do with increasing marginal costs?  And might not
increasing marginal costs have something to do with, e.g., the
near-saturation levels of Japanese fertilizer usage?  I really don't
know the reasons for the relatively low yield increases despite strong
price supports and the comparative sophistication of Japanese farmers,
but surely the reasons are worth investigating.

>Perhaps you should ask yourself, "how much rice would the world have
>produced if all rice farms were as productive as the average Japanese
>farm?"  I suspect the number would be very large (so large that it
>would be senseless to make the investment needed to achieve that end).

According to Brown, "the 1989 rice yield in China, the world's largest
rice producer, was an estimated 3.8 tons of milled rice per hectare,
exactly the same as Japan's rice yield in 1970.  Today, yield per
hectare of corn in the United States is nearly double that of rice in
Japan in 1970.  The yield of wheat in Western Europe is currently a
fourth again as high.  On the other end of the scale, 1989 rice yields
in India were less than half those of Japan in 1970" [Ibid., p. 76].
We should ask ourselves, not what if all rice farms were as productive
as Japan's (this will take a significant time span to achieve), but
whether the world can increase grain yields by at least 1.7% per year,
about twice the Japanese rate in the last two decades, during the 90s
and beyond in order to keep up with population growth.

Richard Carnes