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by Paul and Anne Ehrlich

Having considered some of the ways that humanity is destroying its inheritance, we can look more closely at the concept of "overpopulation." All too often, overpopulation is thought of simply as crowding: too many people in a given area, too high a population density. For instance, the deputy editor in chief of Forbes magazine pointed out recently, in connection with a plea for more population growth in the United States: "If all the people from China and India lived in the continental U.S. (excluding Alaska), this country would still have a smaller population density than England, Holland, or Belgium." *31

The appropriate response is "So what?" Density is generally irrelevant to questions of overpopulation. For instance, if brute density were the criterion, one would have to conclude that Africa is "underpopulated," because it has only 55 people per square mile, while Europe (excluding the USSR) has 261 and Japan 857. *32 A more sophisticated measure would take into consideration the amount of Africa not covered by desert or "impenetrable" forest. *33 This more habitable portion is just a little over half the continent's area, giving an effective population density of 117 per square mile. That's still only about a fifth of that in the United Kingdom. Even by 2020, Africa's effective density is projected to grow to only about that of France today (266), and few people would consider France excessively crowded or overpopulated.

When people think of crowded countries, they usually contemplate places like the Netherlands (1,031 per square mile), Taiwan (1,604), or Hong Kong (14,218). Even those don't necessarily signal overpopulation—after all, the Dutch seem to be thriving, and doesn't Hong Kong have a booming economy and fancy hotels? In short, if density were the standard of overpopulation, few nations (and certainly not Earth itself) would be likely to be considered overpopulated in the near future. The error, we repeat, lies in trying to define overpopulation in terms of density; it has long been recognized that density per se means very little. *34

The key to understanding overpopulation is not population density but the numbers of people in an area relative to its resources and the capacity of the environment to sustain human activities; that is, to the area's carrying capacity. When is an area overpopulated? When its population can't be maintained without rapidly depleting nonrenewable resources (or converting renewable resources into nonrenewable ones) and without degrading the capacity of the environment to support the population. In short, if the long-term carrying capacity of an area is clearly being degraded by its current human occupants, that area is overpopulated. *35

By this standard, the entire planet and virtually every nation is already vastly overpopulated. Africa is overpopulated now because, among other indications, its soils and forests are rapidly being depleted—and that implies that its carrying capacity for human beings will be lower in the future than it is now. The United States is overpopulated because it is depleting its soil and water resources and contributing mightily to the destruction of global environmental systems. Europe, Japan, the Soviet Union, and other rich nations are overpopulated because of their massive contributions to the carbon dioxide buildup in the atmosphere, among many other reasons.

Almost all the rich nations are overpopulated because they are rapidly drawing down stocks of resources around the world. They don't live solely on the land in their own nations. Like the profligate son of our earlier analogy, they are spending their capital with no thought for the future.

It is especially ironic that Forbes considered the Netherlands not to be overpopulated. This is such a common error that it has been known for two decades as the "Netherlands Fallacy." *36 The Netherlands can support 1,031 people per square mile only because the rest of the world does not. In 1984-86, the Netherlands imported almost 4 million tons of cereals, 130,000 tons of oils, and 480,000 tons of pulses (peas, beans, lentils). It took some of these relatively inexpensive imports and used them to boost their production of expensive exports—330,000 tons of milk and 1.2 million tons of meat. The-Netherlands also extracted about a half-million tons of fishes from the sea during this period, and imported more in the form of fish meal. *37

The Netherlands is also a major importer of minerals, bringing in virtually all the iron, antimony, bauxite, copper, tin, etc., that it requires. Most of its fresh water is "imported" from upstream nations via the Rhine River. The Dutch built their wealth using imported energy. Then, in the 1970s, the discovery of a large gas field in the northern part of the nation allowed the Netherlands temporarily to export as gas roughly the equivalent in energy of the petroleum it continued to import. But when the gas fields (which represent about twenty years' worth of Dutch energy consumption at current rates) are exhausted, Holland will once again depend heavily on the rest of the world for fossil fuels or uranium. *38

In short, the people of the Netherlands didn't build their prosperity on the bounty of the Netherlands, and are not living on it now. Before World War II, they drew raw materials from their colonies; today they still depend on the resources of much of the world. Saying that the Netherlands is thriving with a density of 1,031 people per square mile simply ignores that those 1,031 Dutch people far exceed the carrying capacity of that square mile.

This "carrying-capacity" definition of overpopulation is the one used in this book. *39 It is important to understand that under this definition a condition of overpopulation might be corrected with no change in the number of people. For instance, the impact of today's 665 million Africans on their resources and environment theoretically might be reduced to the point where the continent would no longer be overpopulated. To see whether this would be possible, population growth would have to be stopped, appropriate assistance given to peasant farmers, and certain other important reforms instituted. Similarly, dramatic changes in American lifestyle might suffice to end overpopulation in the United States without a large population reduction.

But, for now and the foreseeable future, Africa and the United States will remain overpopulated—and will probably become even more so. To say they are not because, if people changed their ways, overpopulation might be eliminated is simply wrong—overpopulation is defined by the animals that occupy the turf, behaving as they naturally behave, not by a hypothetical group that might be substituted for them. [p.p. 37-40, Paul and Anne Ehrlich, THE POPULATION EXPLOSION; Simon and Schuster, 1990. Phone: 212-698-7000]

Cairo, 5 - 13 September 1994
Weighing Relative Burdens on the Planet
by Paul Ehrlich

Concern about population problems among citizens of rich countries generally focuses on rapid population growth in most poor nations. But the impact of humanity on Earth's life support systems is not just determined by the number of people alive on the planet. It also depends on how those people behave. When this is considered, an entirely different picture emerges: the main population problem is in wealthy countries. There are, in fact, too many rich people.

The amount of resources each person consumes, and the damage done by the technologies used to supply them, need to be taken as much into account as the size of the population. In theory, the three factors should be multiplied together to obtain an accurate measurement of the impact on the planet*. Unhappily, Governments do not keep statistics that allow the consumption and technology factors to be readily measured—so scientists substitute per capita energy consumption to give a measure of the effect each person has on the environment.


In traditional societies—more or less in balance with their environments—that damage may be self-repairing. Wood cut for fires or structures regrows, soaking up the carbon dioxide produced when it was burned. Water extracted from streams is replaced by rainfall. Soils in fields are regenerated with the help of crop residues and animal manures. Wastes are broken down and reconverted into nutrients by the decomposer organisms of natural ecosystems.

At the other end of the spectrum, paving over fields and forests with concrete and asphalt, mining the coal and iron necessary for steel production with all its associated land degradation, and building and operating automobiles, trains and aeroplanes that spew pollutants into the atmosphere, are all energy-intensive processes. So are drilling for and transporting oil and gas, producing plastics, manufacturing chemicals (from DDT and synthetic nitrogen fertilizers to chlorofluorocarbons and laundry detergents) and building power plants and dams. Industrialized agriculture uses enormous amounts of energy—for ploughing, planting, fertilizing and controlling weeds and insect pests and for harvesting, processing, shipping, packing, storing and selling foods. So does industrialized forestry for timber and paper production.


Incidents such as Chernobyl and oil spills are among the environmental prices paid for mobilizing commercial energy—and soil erosion, desertification, acid rain, global warming, destruction of the ozone layer and the toxification of the entire planet are among the costs of using it.

In all, humanity's high-energy activities amount to a large-scale attack on the integrity of Earth's ecosystems and the critical services they provide. These include control of the mix of gases in the atmosphere (and thus of the climate); running of the hydrologic cycle which brings us dependable flows of fresh water; generation and maintenance of fertile soils; disposal of wastes; recycling of the nutrients essential to agriculture and forestry; control of the vast majority of potential crop pests; pollination of many crops; provision of food from the sea; and maintenance of a vast genetic library from which humanity has already withdrawn the very basis of civilization in the form of crops and domestic animals.


The average rich-nation citizen used 7.4 kilowatts (kW) of energy in 1990—a continuous flow of energy equivalent to that powering 74 100-watt lightbulbs. The average citizen of a poor nation, by contrast, used only 1 kW. There were 1.2 billion people in the rich nations, so their total environmental impact, as measured by energy use, was 1.2 billion x 7.4 kW, or 8.9 terawatts (TW)—8.9 trillion watts. Some 4.1 billion people lived in poor nations in 1990, hence their total impact (at 1 kW a head) was 4.1 TW.

The relatively small population of rich people therefore accounts for roughly two-thirds of global environmental destruction, as measured by energy use. From this perspective, the most important population problem is overpopulation in the industrialized nations.

The United States poses the most serious threat of all to human life support systems. It has a gigantic population, the third largest on Earth, more than a quarter of a billion people. Americans are superconsumers, and use inefficient technologies to feed their appetites. Each, on average, uses 11 kW of energy, twice as much as the average Japanese, more than three times as much as the average Spaniard, and over 100 times as much as an average Bangladeshi. Clearly, achieving an average family size of 1.5 children in the United States (which would still be larger than the 1.3 child average in Spain) would benefit the world much more than a similar success in Bangladesh.


Professor John P. Holdren of the University of California has generated an "optimistic" scenario for solving the population- resource-environment predicament. This envisages population growth halted at 10 billion a century from now, and rich nations reducing their energy consumption to 3 kW a head. His population target is feasible with modest effort, and the reduction in energy consumption could be achieved with technologies already in hand—given the necessary political will—and would produce an increase in the quality of life. This would provide room for needed economic growth in poor nations, which could triple their per-person energy use to 3 kW. Thus the gap between rich and poor nations would be closed, while the total world impact would increase from 13 TW to 30 TW (10 billion x 3 kW).

Will the environment a century hence be able to support 2.3 times as much activity as today? It's questionable, but perhaps with care it could, at least temporarily. Success would require a degree of cooperation, care for our fellow human beings, and respect for the environment that are nowhere evident now. But society has shown it can change rapidly when the time is ripe; let us hope that the United Nations International Conference on Population and Development will help ripen the time.

* * *

* The relationship is summarized in the classic I=PAT identity: Impact is equal to Population size, multiplied by per capita consumption (Affluence), in turn multiplied by a measure of the damage done by the Technologies chosen to supply each unit of consumption.

Mr. Paul R. Ehrlich is Bing Professor of Population Studies and Professor of Biological Sciences at Stanford University in the United States. His most recent books, both co-authored with his wife Anne, are "The Population Explosion" (Simon and Schuster, 1990) and "Healing the Planet" (Addison-Wesley, 1991). The feature originally appeared in Vol. 6, No.3, 1994 of "Our Planet". The views expressed herein do not necessarily reflect those of UNEP.

UNEP Feature 1994/8


STANFORD—Asserting that there is now a "brownlash" in the form of deceptive books and articles downplaying environmental problems, scientists from Stanford's Department of Biological Sciences challenged Julian Simon to bet on significant trends in the human future.

Simon, a professor of business administration at the University of Maryland, has repeatedly claimed that all environmental trends are positive and that "doomsaying environmentalists" are wrong. In the San Francisco Chronicle of Friday, May 12, he suggested environmentalists bet that "any trend pertaining to material human welfare" will get worse, since Simon writes they will "all" get better.

The Stanford scientists, ecologist Paul R. Ehrlich and climatologist Stephen H. Schneider actually challenged Simon to bet on 15 current trends whose direction is not positive now, betting $1000 that each will get worse over a ten year stretch into the future. They pledged themselves to be bound by the decision of "a panel of scientists chosen by the President of the National Academy of Sciences in 2005."

Among the negative trends they bet would continue were:

* Rising global temperature.
* Shrinking amount of cropland per person.
* Decline in amount of wheat and rice grown per person.
* Shrinking area of tropical moist forests.
* Decreasing oceanic fish harvest per person.
* Increasing number of people dying of AIDS.
* Declining human sperm count.
* Growing gap between rich and poor.

The Stanford scientists explained that they had chosen "15 trends to avoid the result of a statistical fluke" deciding the bet, as may well have happened in a previous bet on a minor issue marginally related to environmental quality.

They pointed out that the trends in their wager "are more relevant to human welfare than direct ones such as the prices of metals" and that deterioration in those trends "makes society increasingly vulnerable to severe negative impacts."

They concluded "We hope we lose all parts of the bet, and will be doing everything in our power to make that happen.

Sadly, the misinformation you are spreading, Mr. Simon, increases the chances we will win the bet—while humanity loses."

The complete text of the response sent to the Chronicle follows:

by Paul R. Ehrlich and Stephen H. Schneider

There is now a campaign of deceptive books and articles designed to persuade people that all is well on the environmental front. The basic message of this campaign is that some favorable trends show green concerns to be "doomsaying." Our basic message is that indirect trends such as those listed below are more relevant to human welfare than direct ones such as the prices of metals.

Julian Simon has been a leader in this campaign. He is best known for his belief that resources are infinite (he wrote in 1980 that the theoretical limit to the amount of copper that might be available to human beings was "the total weight of the universe"!) and that population can and should grow indefinitely. He's still at it ("Earth's Doomsayers are Wrong," Chronicle, May 12), this time citing a 1986 report prepared by social scientists for the National Academy of Sciences (NAS) that was subsequently protested by a substantial number of Academy scientists. Somehow he missed the 1994 statement from the NAS and 57 other national academies of science worldwide that contradicted his position.

He also ignored the 1993 "World Scientists' Warning to Humanity," signed by some 1700 leading scientists, including over half of all living Nobel Laureates in science, which reads in part: "A great change in our stewardship of the earth and the life on it is required if vast human misery is to be avoided and our global home on this planet is not to be irretrievably mutilated....A new ethic is required—a new attitude towards discharging our responsibility for caring for ourselves and for the earth. We must recongize the earth's limited capacity to provide for us. We must recognize its fragility....The scientists issuing this warning hope that our message will reach and affect people everywhere. We need the help of many."

It is impossible to say exactly how direct measures of human well-being will be impacted by the general deterioration of Earth's life-support systems. We know, however, that deterioration makes society increasingly vulnerable to severe negative impacts.

One of us (PRE) once made the mistake of being goaded into making a bet with Simon on a matter of marginal environmental importance (prices of metals). Simon says he still wants to make bets. We are thus now challenging Simon to bet on "trends" of much greater significance to long-term human material welfare.

We wager $1000 per trend that each of the following 15 continental and global scale indicators will change in the direction indicated ("get worse") over the next decade:

1. The three years 2002-2004 will on average be warmer than 1992-1994 (rapid climatic 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 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 tropospheric ozone globally will be greater in 2004 than in 1994 (tropospheric ozone has important deleterious effects on human health and crop production)

5. Emissions of sulfur dioxide in Asia will be signficantly greater in 2004 than in 1994 (sulfur dioxide becomes sulphuric acid in the atmosphere, the principal component of acid rain, and it is associated with direct damage to human health).

6. There will be less fertile cropland per person in 2004 than in 1994 (as the population grows, some of Earth's best farmland is being paved over).

7. There will be less agricultural soil per person in 2004 than in 1994 (about a quarter of the world's topsoil has been lost since World War II, and erosion virtually everywhere far exceeds rates of soil replacement).

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 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 (continuing habitat destruction is wiping out organisms that 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 off in Asia).

14. Between 1994 and 2004, sperm counts of human males will continue to decline and reproductive disorders to increase (over the last 50 years there has been a roughly 40 percent decline in the count worldwide. We bet this trend will continue due to the widespread use 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.

We "doomsayers," of course, are not arguing that there are only unfavorable human or environmental trends, rather that too many of the most important are very unfavorable and thus demand prompt attention. Virtually all long-term trends have short-term fluctuations, thus we challenge Simon on 15 trends to avoid the result of a statistical fluke deciding this bet. To determine the direction of the trends, we will accept the decision of a panel of scientists chosen by the President of the National Academy of Sciences in 2005. Referees will be necessary, since terms like "significantly" (e.g., 5 and 10 above) and estimates of such things as agricultural soils involve questions of judgment. But there is an empirical basis on which competent scientists can make reasonable judgments.

The bet is binding on our heirs, and our winnings will go to non-profit organizations dedicated to preserving environmental quality and human well-being. Since humanity is gambling with its life-support systems, we hope to lose all parts of the bet.

In fact, we will be doing everything in our power to make that happen. Sadly, the complacency and misinformation you are spreading, Mr. Simon, increases the chances we will win the bet—while all of humanity loses. We hope this wager will cause you to reconsider the risks you so blythly suggest the American public undertake by promoting the fantasy of benign indefinite growth.

Paul R. Ehrlich and Stephen H. Schneider are Professors in the Department of Biological Sciences, Stanford University.

A review of:
by Herman Daly

This book is an all-out attack on neomalthusian or limits-to-growth thinking and a plea for more population and economic growth, both now and into the indefinite future. It is not a shotgun attack. Rather it is an attack with a single-shot rifle aimed at a single (but critical) premise of the neomalthusian position.

If Simon hits the target, then neomalthusian arguments collapse. If Simon misses the target, then all neomalthusian first principles remain unscathed, and Simon's progrowth arguments collapse. The critical premise that Simon attacks is that of the finitude of resources, including waste absorption capacities. Other premises from which neomalthusians argue include the entropy law and the vulnerability of ecological life-support services.

Simon's theoretical argument against the finitude of resources is that:

"The word "finite" originates in mathematics, in which context we all learn it as schoolchildren. But even in mathematics the word's meaning is far from unambiguous. It can have two principal meanings, sometimes with an apparent contradiction between them. For example, the length of a one-inch line is finite in the sense that it bounded at both ends. But the line within the endpoints contains an infinite number of points; these points cannot be counted, because they have no defined size. Therefore the number of points in that one-inch segment is not finite. Similarly, the quantity of copper that will ever be available to us is not finite, because there is no method (even in principle) of making an appropriate count of it, given the problem of the economic definition of "copper," the possibility of creating copper or its economic equivalent from other materials, and thus the lack of boundaries to the sources from which copper might be drawn."

Two pages later he drives home the main point in connection with oil:

"Our energy supply is non-finite, and oil is an important example . . . the number of oil wells that will eventually produce oil, and in what quantities, is not known or measurable at present and probably never will be, and hence is not meaningfully finite."

The fallacy in the last sentence quoted is evident. If I have seven gallons of oil in seven one gallon cans, then it is countable and finite. If I dump one gallon of oil into each of the seven seas and let it mix for a year, those seven gallons would no longer be countable, and hence not "meaningfully finite, " therefore infinite. This is straightforward nonsense.

The fallacy concerning the copper is obscured by the strange fact that Simon begins with a correct distinction regarding infinity of distance and infinity of divisibility of a finite distance, and then as soon as he moves from one-inch lines to copper with nothing but the word "similarly" to bridge the gap, he forgets the distinction. It would be a wonderful exercise for a class in freshman logic to find the parallel between Simon's argument and Zeno's paradox of Achilles and the tortoise. Recall that Zeno "proved" that Achilles could never catch up with a tortoise that had a finite head start on him. While Achilles traverses the distance from his starting point to that of the tortoise, the tortoise advances a certain distance, and while Achilles advances this distance, the tortoise makes a further advance, and so on, ad infinitum. Thus Achilles will never catch up.

Zeno's paradox confounds an infinity of subdivisions of a distance, which is finite, with an infinity of distance. This is exactly parallel to what Simon has done. He has confused an infinity of possible boundary lines between copper and noncopper with an infinity of amount of copper. We cannot, he says, make an "appropriate count" of copper because the set of all resources can be subdivided in many ways with many possible boundaries for the subset copper because resources are "infinitely" substitutable. Since copper cannot be simply counted like beans in a jar, and since what cannot be counted is not finite, it "follows" that copper is not finite, or copper is infinite.

Simon has argued from the premise of an "infinite" substitutability among different elements within a (finite) set to the conclusion of the infinity of the set itself. But no amount of rearrangement of divisions within a finite set can make the set infinite. His demonstration that mankind will never exhaust its resource base rests on the same logical fallacy as Zeno's demonstration that Achilles will never exhaust the distance between himself and the tortoise. Simon's argument therefore fails even if we grant his premise of infinite substitutability, which gets us rather close to alchemy. Copper is after all an element, and the transmutation of elements is more difficult than the phrase "infinite substitutability" implies! Indeed, Simon never tells us whether "infinite substitutability" means infinite substitutability at declining costs, constant costs, increasing costs, or at infinite costs! Of course Simon could simply assert that the total set of all resources is infinite, but this would be a bald assertion, not a conclusion from an argument based on substitutability, which is what he has attempted.

Simon appeals to the unlimited power of technology to increase the service yielded per unit of resource as further evidence of the essentially nonfinite nature of resources. If resource productivity (ratio of service to resources) were potentially infinite, then we could maintain an ever growing value of services with an ever smaller flow of resources. If Simon truly believes this, then he should join those neomalthusians who advocate limiting the resource flow precisely in order to force technological progress into the direction of improving total resource productivity and away from the recent direction of increasing intensity of resource use. Many neomalthusians advocate this even though they believe the scope for improvement is finite. If one believes the scope for improvement in resource productivity is infinite, then all the more reason to restrict the resource flow.

Those who are loud in their praise of Simon are the same people who would have bet on the tortoise, and are now betting on infinite resources. Simon's ultimate criterion for the validity of an argument seems to be willingness to "put your money where your mouth is." (See his grandstand offer on page 27 to bet anyone any amount, up to a $10,000 total, that the real price of any resource will not rise.) He suggests that the current heavy betting by speculators that the resource tortoise will stay ahead of the Achilles of demographic and economic growth is the best available evidence of the final outcome of the race. But it could in fact be the best available evidence that speculators are interested only in the short run, or that there is a sucker born every minute! In any case "put your money where your mouth is" is a challenge to intensity of belief, not correctness of belief. It is the adman's customary proof by bombastic proclamation.

But what about Simon's empirical evidence against resource finitude? It fares no better than his fallacious attempt at logical refutation. He leans heavily on two expert studies: "The Age of Substitutability" by Weinberg and Goeller (Science, February 20,1976), and Scarcity and Growth by Barnett and Morse.*1 His use of these studies is amazingly selective.

From Weinberg and Goeller he quotes optimistic findings of "infinite" substitutability among resources, assuming a future low-cost, abundant energy source. This buttresses Simon's earlier premise of "infinite" subdivisibility or substitutability among resources. But it does not lend support to his fallacious conclusion that resources are infinite and therefore growth forever is possible. More to the point, however, is that Weinberg and Goeller explicitly rule out any such conclusion by stating in their very first paragraph that their "Age of Substitutability" is a steady state. It assumes zero growth in population and energy use at the highest level that Weinberg and Goeller are willing to say is technically feasible. And they express serious reservations about the social and institutional feasibility of maintaining such a high consumption steady state.

Furthermore, the levels envisioned by Weinberg and Goeller, though cornicopian by general consent, are quite modest by Simon's standards: world population in the Age of Substitutability would be only 2.5 times the present population, and world energy use would be only 12 times present use. This implies a world per-capita energy usage of only 70 percent of current U.S. per capita use. The very study that Simon appeals to for empirical support of his unlimited growth position explicitly rejects the notion of unlimited growth—a fact that Simon fails to mention.

As further empirical evidence we are served a rehash of the Barnett an Morse study. Their finding was that the scarcity of most resources, as measure by per unit extractive costs and by relative prices, was decreasing rather than increasing from 1870 to 1957. Simon gives these arguments as evidence the resources are infinite.

There is no serious dispute about the Barnett and Morse numbers, but the conclusion that resources are becoming ever less scarce is hardly justified. The neomalthusians can reply that of course the prices of resources fall during a epoch of mineralogical bonanza. But the data cannot be decisive between these two views, since they cover only that epoch.

Barnett and Morse are careful to report an important exception to the general finding of falling resource prices: timber, whose price increased during the period. Simon's way of handling this exception is interesting. He first considers only mineral resources and applies the criterion of price as a measure of scarcity, explicitly rejecting all quantity-based indices. He thus shows, decline in scarcity of mineral resources. Later, in the context of food, he considers timber. This is a fair enough context, except that he switches his criterion of scarcity from price to quantity of timber growth. In this way he ca show decreasing timber scarcity by applying quantity measures, while showing decreasing minerals scarcity by applying price measures.

But an equally shifty neomalthusian could use quantity remaining in the ground to prove increasing scarcity of minerals, and relative price to prove increasing scarcity of timber. There is a serious debate about the proper measure of scarcity, as the report by Resources for the Future, Scarcity and Growth Reconsidered,*2 demonstrates, but Simon is not engaged in that serious discussion. He grabs whatever number may be moving in the direction that fits the needs of the argument at hand and baptizes it as an index of whatever he is talking about. Two examples will illustrate:

First, Simon claims, after warning us to "grab your hat," that pollution has really been decreasing rather than increasing. To test this hypothesis most investigators would probably look at parts per million of various substances emitted into the air and water by human activities to see if they have been rising or falling over time. Simon, however, takes life expectancy as his index of pollution: increasing life expectancy indicates decreasing pollution. If one suggests that the increase in life expectancy mainly reflects improved control of infectious diseases, Simon redefines "pollutant" to include the smallpox virus and other germs. In this way an increase in emissions of noxious substances from the economy (what everyone but Simon means by "pollution") would not register until after it more than offset the improvement in life expectancy brought about by modern medicine. Thus Simon "measures" pollution by burying it in an aggregate, the other component of which offsets and overwhelms it.

The second example is the claim (we are again told to grab our hats) that the combined increases of income and population do not increase "pressure" on the land. His proof: the absolute amount of land per farm worker has been increasing in the United States and other countries. One might have thought that this was a consequence of mechanization of agriculture and that the increasing investment per acre in machinery, fertilizer, and pesticides represented pressure on the land, not to mention pressure on mines, wells, rivers, lakes, and so on.

Simon's demonstration that resources are infinite is, in my view, a coarse mixture of simple fallacy, omission of contrary evidence from his own expert sources and gross statistical misinterpretation. Since everything else hinges on the now exploded infinite resources proposition, we could well stop here. But there are other considerations less central to the argument of the book that beg for attention.

If, Simon notwithstanding, resources are indeed finite, then the other premises of the neomalthusians remain in vigor. The entropy law tells us not only that coal is finite, but that you can't burn the same lump twice. When burned, available energy is irreversibly depleted and unavailable energy is increased along with the dissipation of materials. If nature's sources and sinks were truly infinite, the fact that the flow between them was entropic would hardly matter. But with finite sources and sinks, the entropy law greatly increases the force of scarcity.

Although the words "entropy" or "second law of thermodynamics" remarkably do not occur once in a 400-page book on The Ultimate Resource, the concept is occasionally touched upon. There is a comment made in passing that marble and copper can be recycled, whereas energy cannot. This raises hopes that Simon may not be ignorant of the entropy law. These hopes are soon dashed when he softens the statement to "energy cannot be easily recycled." Later he tells us that "man's activities tend to increase the order and decrease the homogeneity of nature. Man tends to bring like elements together, to concentrate them."

That is the only part of the picture that Simon knows about. But the entropy law tells us there is another part—that to increase order in one part of the system requires the increase of disorder elsewhere, and that in net terms for the system as a whole the movement is toward disorder. In other words, more order and more matter and energy devoted to human bodies and artifacts mean less matter and energy and less order for the rest of the system, which includes all the other species on whose life-support services we and our economy depend. Simon is quite prepared to ruin the habitats of all other species by letting them (and future generations) bear the entropic costs of disorders that our own continuing growth entails. For Simon, however, this problem cannot exist because he believes resources and absorption capacities are infinite. But after he has once mastered the paradox of Achilles and the tortoise concerning infinity, his next homework assignment should be to find out about entropy. Until he has done these two things he should stop trying to write books for grownups about resources and population.

Part II of the book is on population and is dedicated to the proposition that the ultimate resource is people. The more the better, indefinitely. We are told that: "Even the proposition that population growth must stop sometime may not be very meaningful (see Chapter 3 on 'finitude')." We have already seen Chapter 3 on finitude and have discovered that it is sheer nonsense. I will spare the reader a recitation of all the propositions about population that self-destruct with the demise of Chapter 3.

There is a puzzling methodological inconsistency between Parts I and II. In Part I Simon is the total empiricist, trusting only in the extrapolation of recent trends of falling resource prices. Any a priori argument from first principles about reversal of trends due to increasing cost, diminishing returns, the end of a bonanza, or even the S-shape of the logistic curve characteristic of all empirically observed growth processes simply does not warrant consideration by this hard-headed empiricist. Yet in Part II we find Simon refusing to project population trends and relying on the theory of demographic transition to reverse the recent trend of population growth. His own graphs, used to demonstrate the unreliability of past population predictions, also show that a simple linear trend would have yielded much more accurate predictions in the 1920s than did the then current "twilight of parenthood" theories. Once again, whatever epistemological posture serves the immediate needs of argument is adopted. One is certainly free to choose whatever balance of theory and empiricism one thinks is most effective in getting at the truth, but the balance should not fluctuate so wildly, so often, and so opportunistically.

Simon values human life. More people are better than fewer people because each additional person's life has value for that person, his loved ones, and for society as a whole should he turn out to be a genius: an increase of 4,000 people is more likely to yield another Einstein, Mozart, or Michelangelo than an increase of only 400 people.

While I personally give zero weight to the notion that more births among today's poor and downtrodden masses will increase the probability of another Einstein or Mozart (or Hitler or Caligula?), I do agree that, other things equal, more human lives, and more lives of other species, are better than fewer. And I think that most of my fellow neomalthusians would agree than 10 billion people are better than 2 billion—as long as the 10 billion are not all alive at the same time!

This is the crucial point: neomalthusian policies seek to maximize the cumulative total of lives ever to be lived over time, at a sufficient per-capita standard for a good life. Simon wants to maximize the number of people simultaneously alive—and, impossibly, to maximize per-capita consumption at the same time. These two contradictory strategies are possible only if resources are infinite. If they are finite then maximizing the number of simultaneous lives means a reduction in carrying capacity, fewer people in future time periods, and a lower cumulative total of lives ever lived at a sufficient standard.

The difference is not, as Simon imagines, that he is "pro-life" and the neomalthusians are "anti-life." Rather it is that neomalthusians have a basic understanding of the biophysical world, whereas Simon still has not done his homework on Zeno's paradoxes of infinity, on the entropy law, on the importance of ecological life-support services provided by other species, and on the impossibility of the double maximization implied in his advocacy of "the greatest good for the greatest number."

Simon seems to believe that an avoided birth today implies the eternal nonexistence of a particular self-conscious person who would have enjoyed life. But as far as I know, the pairing of a particular self-consciousness with a particular birth is the greatest of mysteries. Perhaps birth control means that a particular existence is postponed rather than canceled. In other contexts, however, Simon proclaims that "birth control is simply a human right." When Kingsly Davis, Paul Ehrlich, or Garret Hardin advocate birth control they are sacrificing the unborn; but when Simon finds it convenient to his argument to endorse birth control, he is proclaiming a human right.

In this reviewer's opinion, Simon's book cannot stand up to even average critical scrutiny. Lots of bad books are written, and the best thing usually is to ignore them. I would have preferred to ignore this one, too, but judging from the publicity accorded Simon's recent articles, this book is likely to be hailed as a triumph by people who are starved for "optimism." Simon himself tells us that the optimistic conclusions he reached in his population studies helped to bring him out of a "depression of medically unusual duration," and he clearly wants to share the cure. But his cure is at best a sugar pill.

We must abandon the shallow, contrived optimism of growthmania once and for all. The end of growthmania is no cause for despair; it is a hopeful new beginning. To me the optimistic alternative is that of a steady state at a sufficient, sustainable level in which many future generations can rejoice in the loving study and care of God's creation.

Further prolongation of the current compulsive quest for infinite growth, power, and control is what I find depressing. We should learn to be good stewards of what is already under our dominion rather than seek always to enlarge that dominion. We who have done a poor job of managing a small domain should not trust ourselves to take over control of an ever larger "infinite" domain.

NOTE: This review appeared originally in Bulletin of the Atomic Scientists, January 1982.


1. Harold Barnett, and Chandler Morse, Scarcity and Growth (Baltimore: Johns Hopkins Press, 1963).

2. V. Kerry Smith, ed., Scarcity and Growth Reconsidered (Baltimore: Johns Hopkins Press, 1979).


The above review is from: [p.p. 282-289] STEADY STATE ECONOMICS, Daly; Island Press, 1991. ISBN 1-55963-071-X