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 22:17:19 GMT

dietz@cs.rochester.edu (Paul Dietz) quotes from a New York Times
Magazine piece by John Tierney (Dec. 2, 1990 -- it contains an account
of Paul Ehrlich's lost wager on metal prices with Julian Simon):

> Now consider how Brown analyzes this data.  In a chapter titled
> "The Illusion of Progress" in this year's report, he focuses not
> on the long-term trend but on the blips in the graph in 1988 and
> 1989 -- when prices rose because of factors like drought and a
> United States Government program that took farmland out of
> production.  Looking ahead to the 1990's, Brown writes "The first
> concrete economic indication of broad-based environmental
> deterioration now seems likely to be rising grain prices."
>
> We are barely into the 1990s, but so far Brown's poor track record
> is intact.  Grain prices have plummeted since he published his
> prediction at the start of the year.  

The sentence Tierney quotes from Brown does not mean, "Grain prices
will rise, starting tomorrow," as Tierney seems to think.  It means,
"The first concrete economic impact of general environmental
degradation, when this impact arrives, will probably be rising grain
prices (in constant dollars)."  Further down the same paragraph, Brown
writes, "If world grain production should surge upward in the
nineties, this price rise will be checked.  If, on the other hand, the
world's farmers still have difficulty expanding production at the 28
million tons a year required merely to maintain current per capita
consumption levels, prices could rise dramatically -- as they did in
the mid-seventies." [STATE OF THE WORLD 1990, p. 11]

> The blips in the late 1980's
> caused farmers to do what they always do when prices rise: plant
> more crops.  

Calling the price rises of the late 1980's "blips" begs the question:
whether they are a foretaste of a long-term trend of rising food
prices.  No one knows, unless they have a crystal ball.

Since Brown has published voluminously on agricultural economics for
thirty years, I doubt that the author of the NYT article knows whether
Brown's track record for predictions is good or poor.  But in any case
this is much less important than whether his facts are correct and his
reasoning cogent.  Brown points out that new cropland and fresh water
are becoming scarcer, the marginal returns on the use of fertilizer
are diminishing, topsoil is eroding, forests are shrinking, rangelands
are deteriorating, deserts are expanding, acid rain is falling,
stratospheric ozone is being depleted, greenhouse gases are building
up, the air is being polluted, and biological diversity is being lost,
all of which factors have a negative effect on food production -- and
the Panglossians are telling us not to worry, just look at the falling
prices of the past, as if the future were bound to be a linear
continuation of the past.

Richard Carnes
From: alanm@hpindda.cup.hp.com (Alan McGowen)
Date: Fri, 3 Apr 1992 01:44:35 GMT
Subject: Population Reduction
Organization: HP Information Networks, Cupertino, CA