Human Cultural
Evolution: The Malthusian Theory
by Lynden S.
Williams
Introduction
This is the first of three papers that examine the
‘supply-side’ theory of human cultural evolution and the alternative
‘demand-side’ theory. The
‘supply-side’ theory was expounded by Thomas Malthus in the early 1800’s as The Principle of Population, and in
1830 in a shortened version as A
Summary View of the Principle of Population, referred to generally as the
Malthusian Theory. The ‘demand-side’
theory was laid out by Ester Boserup in her book The Conditions of Agricultural Growth: The Economics of Agrarian
Change under Population Pressure, published in 1965. We will begin with an examination of the
‘supply-side’ (or Malthusian) theory, and turn to the ‘demand-side’ (or
Boserup) theory in the next paper. The
third paper will examine human cultural evolution and argue the Boserup
Theory is the better explanation of how and why those evolutionary processes
occurred, and explore some of the implications.
Many persons with interest in this topic will be
tempted to assume they need not read this first section on the Malthusian
Theory; we have known about that theory
since high school, and have no need to review it. I suggest that text book explanations of
the Malthusian Theory usually emphasize the two postulates Malthus employed
to support his view and often fail to even acknowledge the logical deduction
that constitutes the core of this theory.
Most historians would reject the Malthusian Theory, but when one reads
their work it is often apparent that Theory is prominent in their thinking
(see reference to V. Gordon Childe below).
In order to understand the Boserup Theory, we must have a clear
understanding of the alternative Malthusian Theory.
I am strongly biased against the Malthusian
Theory, but I cannot disprove that Theory.
I can show that the postulates he used to support his theory have been
incorrect over the past 200 years since he espoused them. But that does not preclude the possibility
that the theory may be correct for reasons that he did not state, or correct
in some places or at some times in the past; and it certainly does not
preclude the possibility that it can hold true in the future. I am strongly biased in favor of the Boserup
Theory, but I cannot prove it is correct.
I can demonstrate how and why the Boserup Theory could explain
much of human cultural evolution and why that explanation is far more
persuasive. But that does not preclude
the possibility that the alternative perspective could have produced the same
result, nor can I know with any degree of certainty whether the Boserup
Theory will be relevant to the future of humans.
The Issue
What caused early humanoids to become omnivorous
(the change from vegetarian to a diet that includes meat)? Was that change predictable? Can we know what sorts of individuals or
groups first made that change? What
caused early people to leave their homeland in the hot wet tropics of Africa
and take up residence in the seasonally dry tropical savannas? What caused them to migrate into the
seasonally cold latitudes of Europe? Was
their motive the same as for those who had previously migrated to the
savannas? Did that same motive cause
some groups to become farmers, and later, to develop the urban-industrial
society? If so, we may be able to
identify the ‘prime driver’ in human cultural evolution, and have a real
basis for explaining how and why the transformation of humans from
hunter-gatherers in the hot wet tropics to urban-industrial societies,
covering most of the ice-free land surface of the earth, occurred. And, if there is one more stage in human
cultural evolution, we may have some basis for speculating which societies
will make that transition.
Each stage in human cultural evolution was
coincident with a rapid expansion of the population and therefore must have
also been coincident with a significant expansion in the production of
food. Obviously these two variables
must increase (or decline) in tandem; the human population could not increase
without an increase in the supply of food, and people would not gather or
produce food and other goods unless there was demand. But which is the basic cause and which is
an effect? If an increase in food
production causes or allows people to increase their population then the
‘prime drivers’ of human cultural evolution must have been those individuals
and societies that discovered or learned how to increase the food
supply. If an increase in population
causes people to increase their supply of food, then we need to focus on why
population pressure occurred in one region or among one group, rather than
some other region or group.
For most of human history ‘supply’ consists
primarily of basic food, and changes in ‘demand’ resulted from population
growth or decline. The supply-side
theory holds that increased or decreased production is the cause for changes
in demand—that is, population growth or decline. The demand-side theory holds that an
increase in demand resulting from population growth is usually necessary to
stimulate those innovations and changed methods that would cause supply to
increase. Obviously, basic food is a
small, albeit essential, component of demand in most countries today, and it
constitutes an equally small share of the total supply of goods and
services. However, whether supply and
demand is made up mostly of basic food or a combination of food and other
goods and services, the question remains: Is it increased supply of goods and
services that causes demand to increase, or is it increased demand for those
goods and services that caused the supply to increase? It is argued here that the ‘supply-side’,
or Malthusian Theory, and ‘demand-side’, or Boserup Theory, are equally
relevant today as in the past when the
primary issue related to food production and population growth.
The Malthusian and Boserup Theories imply human
histories that are so contradictory and so divergent in their cause and
effect interpretations, that the two stories can scarcely be recognized as
dealing with the same species on the same planet. Without a clear understanding of both
theories, one cannot have a valid basis for judging the validity of historical
arguments presented. Any serious student
of human cultural evolution must be able to recognize the perspective of the
speaker with regard to the cause and effect relationship between increased
productivity and growth in demand.
Providing that basis for recognizing that perspective and ability to
contrast that perspective with the alternative view, is the purpose of this,
and the following papers.
Ladder of
Civilization
In the Old
Stone Age men relied for a living entirely on hunting, fishing, and gathering
wild berries, roots, slugs, and shellfish.
Their numbers were restricted by the provision of food made for them
by Nature...In Neolithic times men control their own food supply by
cultivating plants and breeding animals...so that... a community can now produce more food than it needs to consume,
and can increase production to meet the requirement of an expanding
population. ...To secure bronze tools
a community must produce a surplus of foodstuffs to support bodies of
specialist miners, smelters, and smiths withdrawn from direct food production.
V. Gordon Childe.[1]
Clearly Childe subscribed to the ‘supply-side’ or
Malthusian Theory of human cultural evolution. That is, he assumed that the plant-animal
symbiosis we call agriculture resulted from discovery or innovation by humans
in a deliberate effort to increase production in order to provide for a
growing population. Many plants and
animals evolved a mutually beneficial symbiosis with one or more other life
forms. That evolutionary process is
well known to biologists and known to occur over a period of thousands of
years. Humans, in contrast to other
life forms, can become aware of this process and greatly speed and refine
it. But do we suppose humans achieved
it as a discovery or innovation? Don’t
we know animals tend to scatter seeds of the plants they consume? Don’t we know that some of those plants
become dependent upon the animal to scatter their seeds, and gradually lose
the ability to fly on the wind or whatever method they used previously to get
themselves planted? Do we suppose
humans were not molded by the same evolutionary processes that designed other
forms of life? And incidentally, why
would early humans have produced more food than they needed? Did they anticipate an urban market where
they could exchange their surplus food for manufactured products?
Similarly, the movie Space Odyssey 2001 included an introductory segment meant to
illustrate the evolution of man as a tool maker and tool user. The scene was set in a tropical grassland
region during the dry season as two clans of pre-humans compete for a water
hole. The clan with the largest and
strongest male wins that competition and the clan of the weaker male is
forced to retreat. Later a male member
of the weaker clan absent-mindedly picks up a short tree limb and in
frustration slaps it at a nearby skull; he notices that the skull is
smashed. He hits at another skull and
gets the same result; one can see and feel the jubilation and exhilaration of
the ‘inventor or discoverer’ of the club.
The next day at the water hole the tide turns against the big strong
male and in favor of our inventive hero.
[Obviously, no historian would have bought into that story. Pre-humans could never have competed on the
savannas without weapons that would bring down the large grassland animals
and allow them to defend themselves against the large predators. And, the issue of why pre-humans, who did
not use the club, had an opposable thumb with which to hold it, was not
addressed.[2]]
These two examples are typical of how human
cultural evolution is generally portrayed—that is, as a struggle up from brute savagery to
civilization, in which each rung in that ladder was achieved by innovation or
discovery. Indeed, the focus of
history is often on the timing of those advances and the individual or group
that achieved the break through that allowed humans to move to a higher level of civilization and
presumably higher level of well-being.
Thus, the discoverers or innovators who are able to bring a more
productive technology or land use system into existence are often considered
the prime drivers in human cultural evolution. In that sense, history is a celebration of
those individuals and groups who made it possible for humanity to escape the forests of Africa and
settle the savannas and later settle the seasonally cold latitudes, to become
food producers rather than hunter-gatherers of wild plants and animals, and
to achieve the urban-industrial lifestyle.
Certainly Thomas Malthus subscribed to that theory of human cultural
evolution.
The “Malthusian Theory” demonstrated how and why
human population growth would lead necessarily to impoverishment or indeed
starvation, unless new methods and technology were sufficient to offset diminishing marginal returns to labor.[3] He was well aware that in the past (prior
to 1800) improved methods of food production were sufficient to provide for a
growing population. He did not,
however, believe innovation could provide for a growing population in the
future. Discussion of the Malthusian
Theory is often confined to the issue of whether introduction of improved
methods and technology can continue to provide for a growing population and
higher levels of well-being in the future, rather than whether or not that
theory, and the human cultural evolution it implies, is correct.
The central tenants of the Malthusian Theory, the
tendency for populations to increase through time and the Law of Diminishing
Returns to Labor, greatly precede Thomas Malthus. Likewise, the view of human cultural
evolution as a struggle up the ladder of civilization with innovation and
discovery being the cause for that progress, has probably been taken as
‘common knowledge’ from the beginning of human speculation about the how and
why of our history. Malthus is
credited with organizing those ideas into a comprehensive theory of cultural
evolution.
History is often presented as a Malthusian
interpretation of the relationship between innovation and population (or
production) growth. Environmentalists
and futurists of other stripes may disavow that Theory. However, their predictions and projections
of the human future are often largely predicated on the Malthusian
interpretation of human cultural evolution.
If we are to understand human cultural evolution and projections of
that past into the future, we need to have a clear understanding of the
fundamental ideas those projections are based upon. And, we need to understand as well that
there is an alternative theory which produces a radically different
interpretation of how and why humans have come to be as we are, and what
changes are to be expected in the future.
The Malthusian
Theory
THE IRON LAW OF WAGES: “In the natural advance of society, the wages of labor will have a
tendency to fall, as far as they are regulated by supply and demand; for the
supply of labor will continue to increase at the same rate, while the demand
for them will increase at a slower rate.” David Ricardo.
The Iron Law of Wages was first stated by Ferdinand
Lassalle, although the theory behind it was formulated earlier by Thomas
Malthus. The essence of the Iron Law
of Wages is that anything that would cause wages to rise above the minimum
subsistence level would set into motion forces (namely an increase in labor
produced by population growth) that would necessarily bring wages back to the
subsistence level. In short, only
absence of food could prevent population growth to, or somewhat beyond, the
capacity of potential production.
Malthus stated:[4] “...we
cannot fail to be struck with a prodigious power of increase in plants and
animals” (p. 44). Using the
example of wheat, he noted that a single acre of wheat can easily yield
sufficient seed to plant six acres the next season, and those six acres could
yield seed for thirty-six acres in the following season; at that rate of
increase the entire surface of the earth could be covered with wheat in just
fourteen years [614 = 78 billion acres; compared to about 37
billion acres of land on earth]. Likewise,
he noted that sheep are able to double their numbers every two years; if we
begin with the number of sheep that can be sustained on one acre of pasture
and double that number every two years, the entire land surface of the earth
would be filled to capacity with sheep in just seventy-six years. Malthus observed that the land surface of
the earth could not be covered with wheat or sheep because: (among other
reasons) ...“it would be impossible for
the most enlightened human efforts to make all the soil of the earth equal in
fertility to the average quality of land now in use” (p. 45). With regard to plants and non-human animals
Malthus concluded: “...notwithstanding
this prodigious power of increase in vegetables and animals, their actual
increase is extremely slow”; because the resource base upon which they
depend cannot be increased at that rate.
In the case of non-human life, he noted that the resource base was
mostly fixed, except to the extent that humans can modify that resource base,
say for cultigens and domestic animals.
Applying this principle of population to human
population growth, Malthus noted that: “It
may be safely asserted, therefore, that population, when unchecked, increases
in a geometrical progression of such a nature as to double itself every
twenty-five years” (p. 52). He
based that assumption on the doubling of the U.S. population between 1795 and
1820 which he ascribed to the abundance of good land resources available to
the population (there was very little immigration into the U.S. between 1795
and 1820). He assumed that all human
populations would double every 25 years if they also had ample productive
resources available to them. A 25-year
doubling period implies a geometric rate of three percent annually, so that
it would take several hundred years to reach the astronomical numbers that
wheat could achieve in fourteen years and sheep in seventy-six years. For example, if 1,000 people maintained a
growth rate of 3 percent annually, in 600 years they would number 50 billion
[1,000 X (1.03^600) = about 50 billion).
Notwithstanding the greater amount of time required, the term
‘prodigious’ is certainly not an improper characterization of the potential
for human population growth. Malthus
noted that: “If his natural capacity of
increase be greater than can be permanently supplied with food from a limited
territory, his increase must be constantly retarded by the difficulty of
procuring the means of subsistence” (p. 45).
Malthus
knew people could increase production by working their land more intensively.
That is, people can space plants closer, cultivate more often, cover plants
with glass to prevent freezing, apply more fertilizer, water plants more
carefully, etc. However, he noted that
in the absence of an increase in farm land, increased food production would
require “the gradual and laborious
improvement of the land already cultivated… (and that) the yearly increment of food would …have a
tendency to diminish, and the amount of the increase of each successive ten
years would probably be less than of the preceding” (p. 52). The economic law of diminishing returns to
labor assures that additional units of labor applied to a constant amount of
land, will (absent a change in methods) result in a reduction in the marginal
(and thus average) return to labor.
Malthus continued: “By the laws
of nature man cannot live without food.
Whatever may be the rate at which population would increase if
unchecked, it never can actually increase in any country beyond the food necessary
to support it” (p. 54). He
stated: “Elevated as man is above all
other animals by his intellectual faculties, it is not to be supposed that
the physical laws to which he is subjected should be essentially different
from those which are observed to prevail in other parts of animated nature. ...suppose that by great attention to
agriculture, its produce could be permanently increased every twenty-five
years by a quantity equal to that which it at present produces...a rate
decidedly beyond any probability of realization (emphasis mine). The
most sanguine cultivators could hardly expect that in the course of the next
two hundred years each farm in this country on an average would produce eight
times as much as it produces at present, and still less that this rate of
increase could continue so that each farm would produce twenty times as much
as at present in five hundred years, and forty times as much in one thousand
years. Yet this would be an
arithmetical progression and would fall short, beyond all comparison, of the
natural increase of population in a geometrical progression” (p. 53).
Malthus also knew that diminishing returns to
labor could be offset by innovation and new technology. He stated: “while improvements in agriculture ... might for some time occasion a
rapid increase of food and population ... These variations, however,
obviously arise from causes which do not impeach the general tendency of a
continued increase of produce in a limited territory to diminish the power of
its increase in (the) future”
(p. 52). Furthermore, he believed the
law of diminishing returns applied to innovation, as well as to labor, land,
and capital. That is, he assumed that
an innovation allowing production to increase from say 30 to 40 bushels per
acre would be more easily achieved than one that increased production from 40
bushels to 50, and indeed he suggested that the potential for such
innovations is very limited, or perhaps absolutely limited; he stated: “..we are indebted wholly to the ignorance
and bad government of our ancestors.
If they had properly called forth the resources of the soil, it is
quite certain that we should not have but scanty means left of further
increasing our food” (p. 57).
Thus, each innovation that increases production will not only serve to
increase the population, but will also limit the potential for new innovation
that could further increase production.
The issue raised by Malthus was not whether human
population growth would continue or stop.
He was certain that it would stop; it would either be stopped by positive checks or it will be stopped
by preventive checks. Either people would continue to do what
comes naturally and soon find growth stopped by hunger and poverty (positive
checks), or we will see that disaster coming and reduce our fertility before
we run out of food (preventive checks).
Given those two options, Malthus (and all other rational people)
preferred the latter. Obviously, Malthus was aware of the fact that humans
could limit their growth by birth control, abortion, and infanticide;
however, he opposed those methods because he believed they were wrong (vice,
as he put it). He therefore
recommended postponement of marriage or abstaining from sex as the
appropriate “preventive checks” on population growth.
Malthus’ objection to birth control and abortion
is not material to his theory, and inclusion of birth control/abortion in
that model does not make the “neo-Malthusian model” new. Malthus’ religious beliefs have nothing to
do with the validity or lack of validity of his theory. [On the other hand, modern Malthusianists
usually emphasize environmental degradation and destruction associated with
population growth, rather than (or in addition to) diminishing returns to
labor and technology, as the essential limit on increased production; in that
sense it is neo-Malthusian.]
Given the dire consequences of population growth,
and Malthus’ belief that the “laboring classes” were unlikely to limit their
growth by preventive checks, he suggested that attempts to limit the
suffering and hunger of the poor (provided at that time by the “poor tax”)
would be counterproductive. He hoped
that only the most desperate would accept such assistance. He stated: “...if it is so discreditable to receive parochial relief, that great
exertions are made to avoid it, and few or none marry with a certain prospect
of being obliged to have recourse to it, there is no doubt that those who
were really in distress might be adequately assisted with little danger of a
constantly increasing proportion of paupers.” If on the other hand, welfare payments are
socially acceptable and sufficient to reduce poverty to the point that...”many marry with the almost certain
prospect of becoming paupers, and the proportion of their numbers to the
whole population is, in consequence, continually increasing, it is certain
that the partial good attained must be much more than counterbalanced by the
general deterioration in the condition of the great mass of the society and
the prospect of its daily growing worse”... then welfare (parochial
relief) will do more harm than good (p. 69).
Both Marx and Engels objected vigorously to
Malthus’ theory. Marx described
Malthus’ essay as schoolboyish, and he accused Malthus of plagiarism and
being self-serving. He attributed the
jubilant reception of Malthus’ work by the English oligarchy as proof of the
work’s attempt to disrupt the efforts by some to improve the lot of
humankind. Marx’s work is often cited
as an alternative to the Malthusian Theory, even though his objections to the
Malthusian Principle of Population
was largely confined to a single footnote, and his labor theory of value did
not challenge Malthus’ contention that increased production is the cause of
population growth, other than suggesting it would be relevant only in
capitalist countries. One can
certainly view the social implications of the Malthusian Theory as
objectionable or even despicable; however, objections based on idealism and
morality do not constitute a valid argument against that theory, and
certainly do not constitute alternative theory.
The Malthusian Theory is frequently misstated as:
Human populations increase geometrically and the food supply increases
arithmetically. In fact, Malthus said
populations would tend to grow geometrically if food and space were
available, but with rare, short term exceptions, food and space will
certainly not be available, and therefore human populations will certainly
not grow geometrically. He said
the arithmetic rate of increase in food production would be the best that
could be hoped for, but with rare short term exceptions, an arithmetic rate of increase would be decidedly beyond any
probability of realization. An
accurate summary of the Malthusian Theory should be stated as his logical
deduction (not the postulates he used to support that deduction), namely:
That the increase in human populations will be constantly retarded by the
difficulty of procuring the means of subsistence, and therefore population
growth is dependent upon a prior or simultaneous increase in the food supply.
That passion
between the sexes would assure that people would tend to have as many
children as they can feed, and that the number of surviving children will
depend upon the amount of food they have, was mostly taken by Malthus as too
obvious to require much elaboration.
He therefore concentrated his efforts on explaining the capacity of
humans to increase their population geometrically, and the Law of diminishing
returns to labor which would, absent more productive methods, result in lower
marginal returns to increased labor, and thus lower average returns for the
total population. The concept of
diminishing returns to labor is now considered to be a universal economic law
so that Malthus’ explanation and defense of that law can be considered
redundant. Likewise, it is clear that
humans and other living creatures have the biological capacity to increase
their numbers geometrically.
Therefore, much of the content of Malthus’ work can now be considered
to be obviously correct.
On the other hand, diminishing returns to
innovation and technology is certainly not accepted today as obviously
true. And, the ‘facts’ that people
have as many children as they can feed, and that the primary limitation on
population growth is the food supply have been false over most of the world
during the past two hundred years, and were probably always false. Humans can (obviously do) limit their
fertility for reasons that are totally unrelated to their ability or
inability to feed additional children.
And, the application of innovation and technology can produce
(obviously has produced) a rapid rate of growth in production of goods and
services, including food.
The Malthusian Theory conforms to the Biological
Law of Zero Population Growth. Whereas
any form of living creature is biologically capable of increasing at a
geometric rate through time, it will certainly not do so over the long
term. Said another way, the long-term
rate of growth of any species has always been, and must always remain, zero
percent. The biological law of zero
population growth must be qualified as follows: First, for some species, the
population may vary radically from decade to decade (from year to year in the
cases of species such as insects and birds) because of short-term
environmental factors, even though the long-term average remains relatively
constant. Second, major changes in
climate may produce periods when the number of individuals of a species will
increase to a new higher carrying capacity and periods when that number will
decrease to a lower carrying capacity. Third, when a species transfers into a
suitable environment where it was previously absent, it will tend to increase
geometrically as an exotic (and may provide a growing food supply for some
other species), until the new environment is filled (or in most cases
overfilled, at the expense of native life forms). And fourth, all species had a beginning and
presumably will have an end; therefore there must have been a time when their
numbers increased and there will be a time when their numbers will decrease
to zero. And, of course, we must
include a fifth exception to the law of zero population growth: a species
that can radically change the environment and methods of production by
cultural rather than biological chance (that is, humans) is capable of
greatly expanding production and thus accommodating vast increases in
population.
By the time of the 1830 restatement of his Principle of Population, Malthus had
become aware that people in some areas of Europe had reduced their fertility
in spite of the apparent fact that they possessed sufficient food for larger
families. That is, an adequate food
supply caused people to reduce their fertility, rather than (in keeping with
his theory) increase the number of children they have. He quotes M. Muret regarding the reduction
in the fertility rate in Switzerland: “But
whence comes it that the country where children escape the best from the
dangers of infancy, and where the mean life (income)...is higher than in any
other, should be precisely that in which the fecundity is the smallest? How comes it again, that of all our
parishes, the one which gives the mean life the highest, should also be the
one where the tendency to increase is the smallest?” (p. 64). That is, the tendency for fertility to be
inversely related to income, which we recognize as almost universal today,
was already apparent in 1830.
Muret (and Malthus) was confused by this
relationship between fertility and the food supply. Muret stated that he would hazard a
conjecture that: “God has wisely
ordered things in such a manner as that the force of life (income) in each
country should be in the inverse ratio of its fecundity”... so that the
better off will not over-people themselves and the poor by their
extraordinary fecundity, will be able to sustain their population (p.
64). Malthus did not appear to agree
with Muret that lower fertility among those with better access to food was
caused by lower fecundity, but simply saw the Switzerland case stated by
Muret as an exception to his theory.
He stated: “There can be little
doubt that in this case the extreme healthiness of the people, arising from
their situation and employments, had more effect in producing the prudential
check to population than the prudential check in producing the extreme
healthiness” (p. 64). That is,
healthiness (higher incomes or better access to food) seemed to be the cause
rather than a consequence of lower fertility—reversing the lines of causation
in his model.
Nevertheless, Malthus did not see this as evidence
that his theory was incorrect. He
noted (with regard to Switzerland): “There
is no land so little capable of providing for an increasing population as
mountainous pastures. And that: ...the actual progress of population is,
with very few exceptions, determined by the relative difficulty of procuring
the means of subsistence and not by the relative natural powers of
increase...” (p. 65). That is,
Malthus mostly rejected the idea that people with higher incomes would tend
to reduce their fertility except as preventive checks intended to prevent
future impoverishment. He held to the
notion that checks on population were mostly related to an insufficient food
supply (positive checks) or fear that population growth would produce such an
insufficiency (preventive checks). In
the case of Switzerland and other healthy populations in Europe, he believed
people used preventive checks (the prudential restraint on marriage) to prevent
over-population and thereby assure that their offspring will share their
healthy lifestyle.
According to the Malthusian Theory population
growth is a dependent variable (dependent upon an increase in food), and
growth in the food supply is an independent variable (independent of population
growth). If we were to graph the
relationship between the number of people and the amount of food according to
the Malthusian Theory, we would put population on the Y-axis and the food
supply on the X-axis, to indicate that an increase or decrease in the food
supply would lead directly to a concomitant increase or decrease in the
population.[5]
Critique of the
Malthusian Theory
With the advantage of hindsight we know that
Malthus was wrong about the disinclination of humans to limit their population
growth unless forced to do so by scarcity or the threat of future
scarcity. European people the world
over, and more recently most Asians and Latin Americans, have greatly reduced
their rate of growth even though they could easily support much larger
populations. Indeed, declining
fertility around the world is more closely associated with abundance than
scarcity; it is the middle and upper classes that are more inclined to reduce
their fertility, and the poor who appear most resistant to that change (as
was observed in the early 1800’s in Europe by Muret). And indeed, it is mostly those populations
with ‘cradle-to-grave’ government care that now experience negative rates of
population growth. We also have
anthropological evidence that hunter-gatherer societies maintain their
populations well below the carrying capacity even though higher fertility
rates are clearly possible. We must
agree that it is possible that there were times and places where people did
or do reproduce as rapidly as possible until they reach the carrying capacity
and face poverty or starvation.
Nevertheless, we have no definitive proof that this was or is
true. Therefore, anyone who holds the
view that some people reproduce until they reach carrying capacity, has a
very large burden of proof to show why those people behave in a manner so
startlingly different from Europeans, Asians, and Latin Americans who clearly
have not behaved in that way.
Malthus also knew that, in contrast to other
animals, humans could increase their numbers without additional space by
changing their method of producing food.
Other species can only accomplish that by biological change, which is
very slow; humans do that by cultural change that can be very fast. Obviously, he was aware that the population
of England was growing, and he knew there had not been a previous die off,
nor did England gain access to additional farm land. England was able to feed more people
because of new methods of production.
Nevertheless, he assumed that possible improvements in farming methods
were severely limited and such innovations would at best provide a temporary
arithmetic increase in food production.
Over the past 200 years increases in agricultural
production proves Malthus’ assumption that such increases would be temporary
was wrong. The human population has
grown geometrically over the past 200 years, and the pace of technological
change in agriculture has been more than adequate to maintain a rate of
increase in food production equal to or exceeding the rate of population
growth. There can be absolutely no
question about this: Malthus has been wrong so far! The world population has doubled three
times since Malthus wrote his essay, and notwithstanding that eight-fold
increase in numbers, the percentage (not just the number) of the world
population very well fed (or overfed) has never been higher. No one believes technological change can
make the food supply infinitely large, but only a great fool thinks no
further increases in production are possible.
A second critique of the Malthusian Theory is
based on biological evolution. We now
know that symbiotic relationships that develop between life forms is driven
primarily by evolution. Animals tend
to scatter the seeds of those plants they gather, causing plants to favor
those characteristics preferred by the gatherer rather than characteristics
that would favor seed dispersion by wind.
Similarly, the mutual dependency, or symbiosis, that develops between
animals is driven by evolutionary processes.
We refer to those plants that become symbiotic with humans as
cultigens, and animals as domestics.
However, the evolutionary processes that produce symbiosis between
life forms is not confined to humans.
Birds plant many of the trees and shrubs that produce the fruits they
consume; that is, the seed passes through the digestive system of the bird
and is expelled (and fertilized) some distance away. Indeed, the purpose of a nutritious ‘fruit’
surrounding a plant’s seeds is precisely to attract an animal to consume it
in order to disburse the seed. Notice
that seeds tend to be toxic or bitter, so that the consumer spits them out,
or have the ability to pass through the digestive system of the consumer and
remain viable when planted and fertilized (for example tomato seeds passing
through humans). Squirrels save nuts
in an underground cache, which (because of their high mortality rate) they
often fail to retrieve, and thus plant. Notice that nut trees prevent consumption
of their seeds by large grazing animals (that would not plant them) by
producing a very hard shell around the seed, or a poison spot (such as the
buckeye tree), which the squirrel can easily open or chew around.[6] Obviously, domestication differs for humans
because they become aware of the process and take measures to speed and
control it. But, that awareness must
come many thousands of years after the evolutionary process has been
underway.
The fact that the two postulates Malthus used to
support his theory have proven to be false means his logical deduction (that
increased production is the cause for population growth) is not necessarily
true. However, it is possible that
Malthus’ deduction is true for reasons other than those he articulated, or
that they are true in some places but not others. For example, if the production systems that
have provided for the vast increase in the world population cannot be maintained
in a sustainable manner, then the Malthusian Trap has simply been postponed,
rather than avoided. Nevertheless,
Neo-Malthusians have a heavy burden of proof to explain how and why some
human populations will tend to increase their numbers until they reach the
carrying capacity and face starvation, and why population growth will not
stimulate the development of technology needed to allow production to
increase, as it has in the past.
Likewise, sustainability has always been a work in progress; we need
some theory or evidence to suggest that people will be unable or unwilling to
correct the deleterious impacts of their production methods, as they
generally have in the past.
In
hindsight it is difficult to understand how Malthus could have been unaware
of the power of innovation and new technology. After all, he lived in the very heart of
the industrial revolution.
Nevertheless, before we become too critical of Malthus, we must ask
ourselves: How can some modern scholars believe the earth has now reached the
limit on food and other production, believe the land and raw materials will
soon be used up, and believe there cannot be new ways of doing things? Modern Malthusianist Paul Ehrlich (who
wrote The Population Bomb in the late 1960’s) stated (in his widely
read Playboy interview, Aug. 1970) that Malthus was essentially
correct, he just got his timing wrong (by not anticipating the flood of
innovation that accompanied the industrial revolution). Ehrlich stated: “we now know almost exactly what
future innovations are possible” [what an incredible statement!], and
given the most optimistic assessment they could not possibly provide for the
growing human population beyond a few more years. Ehrlich predicted mild food rationing in
the U.S. by 1975 (by which time most of the darker skinned persons in Africa,
Asia, and Latin America would have mostly starved), with the world population
declining to two billion by the year 2000, and leveling off at perhaps one
billion later. He also predicted that
we would run out of many minerals and other raw materials so that the modern
industrial system would cease to operate.
Ehrlich was totally wrong about everything he wrote in his book and
stated in his Playboy interview; however, that has not diminished his
giant stature within the radical environmental movement.[7] Of course, pessimistic futurists have
always looked into the bag of future innovations and, finding it empty,
declared that no such innovations could be possible; said another way,
pessimistic futurists are not innovators!
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[1] V.
Gordon Childe, Man Makes Himself, New York: New American Library, 1951.
[2] Environment
creates form: Notice that fish, sea mammals (seals, dolphins, whales), and sea
birds (penguins), all have the same shape—designed by their ocean environment. Likewise, the club reversed the thumb to the
hand. Chimps can use clubs, but obviously
they have not used them long enough to fully oppose the thumb to the hand. And, there is no way early humans could have
survived on the savannas without weapons that would allow them to compete
against the very aggressive predators and be able to kill the large animals
that inhabit that climate zone.
[3] The
‘marginal return’ to labor is the additional increase in production resulting
from the last worker; the economic Law of Diminishing ‘Marginal’ Returns to
labor affirms that at some point an
additional worker will necessarily produce less. Take the extreme case: a plot of land may
require at least two workers to achieve a harvest; thus hiring the second
worker may result in increasing ‘marginal’ returns. A third worker may also increase total
returns, but not as much as the second worker.
The third worker would be hired only if the lower return exceeds the
wage. Likewise, a forth worker on the
same plot may also increase production, but not as much as the third or
second. We say the wage (plus benefits
and administrative costs) must equal the marginal return to labor. At some point, hiring an additional worker
will not compensate the owner sufficiently to pay the wage; and, of course
there is a point at which an additional worker will result in no additional
return. After the ‘marginal return’ to
labor begins to decline, obviously the average return per worker will also
decline.
4 When
we graph the relationship between two variables we place, by convention, the
independent or cause variable on the X or horizontal axis and the dependent or
result variable on the Y or vertical axis.
For example, if we plot the relationship between income and life
expectancy we would place income on the X or horizontal axis and life
expectancy on the Y or vertical axis, suggesting that higher incomes causes
increased life expectancy (because of better health care, and because we see no
reason why longer life expectance would cause higher income).
[6] I
am not suggesting that plants and animals design their evolutionary processes
purposefully to achieve some desirable goal.
Some plants and animals lucked into a superior method of spreading their
seed or increasing their food supply through the evolutionary process of
symbiosis with other life forms; that process does not require purposeful
action or even awareness. I am
suggesting that the same evolutionary processes explain the domestication of
plants and animals by humans as well.
[7] I
attended a conference at La Selva
research station in Costa Rica in the early 1980’s at which Paul Ehrlich was
present. At one point a Costa Rican
scholar was presenting a paper dealing with some aspect of tropical
biology. Ehrlich interrupted the
presentation with the question of why Costa Ricans were not dealing with their
‘overpopulation’ problem. The question
was in such poor Spanish that only an English speaker with some knowledge of
Spanish or a Spanish speaker with some knowledge of English could have understood. The man responded that he did not believe
Costa Rica had an ‘overpopulation’ problem, and that was not the topic of his
presentation. Ehrlich continued his
questioning until the gentleman finally gave up his presentation and sat
down. I know that many persons in
attendance were very upset by that outburst.
Perhaps some subscribed to Ehrlich’s ‘Population Bomb’ theory; but we
all knew that to challenge Environmentalist
Saint Paul Ehrlich would be a fatal mistake.
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