Make sure you read about Malthusian theory and then watch this video entitled “How many people can live on planet earth?”
https://digital-films-com.ezproxy.cameron.edu/p_ViewVideo.aspx?xtid=41688
After you read and watch the video, apply what you learned by writing a 500–750-word essay and explain:
What you think is in store for the world’s population problem and do you think Malthus’ theory is correct or incorrect?
Here are some ideas to help.
1. Explain the main ideas of Malthus’ theory.
2. Apply some of the topics in the video and chapter and relate them to Malthus’ theory.
3. What are some of the major population problems of the world? Where are most of these problems in the world? (the maps in the chapter can help). Apply the fundamental attributes of demography (migration, population density, total fertility rate, mortality rate are a few examples) to analyze problems that you observe.
Malthusian Theory
One of the first social scientists to tackle the matter of population growth and its consequences was the British Reverend Thomas Robert Malthus. Malthus’s ideas, contrived in the early days of the Industrial Revolution in the late eighteenth century, had an enormous impact on the subsequent understanding of this topic. He offered his most concise explanation in his 1798 book, Essay on the Principle of Population Growth. Malthus was concerned with the growing poverty evident in British cities at the time, and his explanation was largely centered on the high rates of population growth that he observed, which are common to early industrializing societies. Thus, it is with Malthus that the theory of overpopulation originates. His pessimistic worldview earned economics the label of the “dismal science” and stood in sharp contrast to the utopian socialism emanating from France in the aftermath of the French Revolution of 1789.
The essence of Malthus’s line of thought is that human populations, like those of most animal species, grow exponentially (or in the parlance of his times, geometrically). A geometric series of numbers increases at an increasing rate of time. For example, in the sequence 1, 2, 4, 8, 16, 32, and so on, the number doubles at each time period, and the increase rises from 1 to 2 to 4 to 8 and so forth. Exponential population growth, in the absence of significant constraints, is widely observed in bacteria and rodents, to take but a few examples from zoology. Note that there is an important assumption regarding fertility embedded in Malthus’s analysis here: He portrayed fertility as a biological inevitability, not a social construction. This argument was in keeping with the large size of British families at the time and the excess of fertility over mortality. In short, in Malthus’s view, humans, like animals, always reproduced at the biological maximum; they were, and are, portrayed as prisoners of their genetic urges to reproduce. It is worth noting that Reverend Malthus’s argument carried with it a strong moral dimension: It was not just anyone who reproduced rapidly, he observed, but most particularly the poor.
Second, Malthus maintained that food supplies, or resources more generally, grew at a much slower rate than did population. Specifically, he held that the food supply grew linearly (or arithmetically, in his terminology). An arithmetic sequence of numbers, in contrast to an exponential one, grows at a constant rate over time. For example, in the sequence 1, 2, 3, 4, 5, and so on, the difference from one number to the next is always the same. Malthus’s view that agricultural outputs increased linearly over time reflected the preindustrial farming systems that characterized his world. In such circumstances, without economies of scale, an increase in outputs is accomplished only with a proportional increase in inputs such as labor, reflective of what economists call a linear production function. However, this view of agricultural output is actually rather optimistic by Malthus’s reckoning. He argued that in the face of limited inputs of land and capital, agricultural output was likely to suffer from diminishing marginal returns. For example, as farmers moved into areas that were only marginally hospitable to crops, perhaps because they are too dry, too wet, too cold, or too steep, they would need increases in inputs that are proportionately much larger than the increases in output. Diminishing returns, he held, would actually lead to increases in agricultural output that were smaller than a linear production function (with no economies of scale, see Chapter 5) would generate.
When one plots the exponential growth of population against the linear growth of food supplies, it is clear that sooner or later, the former must exceed the latter. Thus, in the Malthusian reading, populations always and inevitably outstrip their resource bases, and people are condemned to suffering and misery as a result. Malthus blamed much of the world’s problems on rapid population growth, and subsequent generations of theorists influenced by his thoughts have invoked overpopulation to explain everything from famine to crime rates to deviant social behavior. Malthus himself entered into a famous debate with his friend David Ricardo over whether the British government should subsidize food for the poor, Malthus maintaining that such subsidies only encouraged the poor to have more children and thus exacerbated poverty in the long run. Indeed, he was contemptuous of the poor, blaming them for their poverty, and even advocating mass death to keep their numbers in check:
Instead of recommending cleanliness to the poor, we should encourage contrary habits. In our towns we should make the streets narrower, crowd more people into the houses, and court the return of the plague. . . . The necessary mortality must come.
Malthusianism thus attributes to rapid population growth a variety of social ills, including poverty, hunger, crime, and disease.
Malthus refined his argument to include checks to population growth. Given that natural population growth is the difference between fertility and mortality, “preventative checks” are factors that reduce the total fertility rate. Contraceptives are an obvious example, although Malthus objected to their use on religious grounds, advocating instead moral restraint or abstinence. Other preventative checks include delayed marriage and prolonged lactation, which inhibits pregnancy. Should preventative checks fail, as he predicted they would, population growth would ultimately be curbed by “positive checks” that increased the mortality rate, particularly the familiar horsemen of the Apocalypse—death, disease, famine, and war.
Malthus’s ideas became widely popular in the late nineteenth century, particularly as they were incorporated into the prevailing social Darwinism of the time, which represented social change in biological terms, often naturalizing competition as a result. However, to many observers it became increasingly apparent that his predictions of widespread famine were wrong. The nineteenth century saw the food supply improve, prices decline, and famine and malnutrition virtually disappear from Europe (except for the Irish potato famine of the 1840s). By the early twentieth century, Malthusianism was in ill repute.
Critics noted that Malthus made three major errors. First, he did not foresee, and probably could not have foreseen, the impacts of the Industrial Revolution on agriculture; the mechanization of food production simply rendered the assumption of a linear increase untenable. Indeed, the world’s supply of food has consistently outpaced population growth, meaning that productivity growth in agriculture has been higher than the rate of increase in the number of people. This observation implies that there is plenty of food to feed everyone in the world and that hunger is not simply caused by overpopulation, but by a variety of other factors, including politics.
Second, Malthus did not foresee the impacts of the opening up of midlatitude grasslands in much of the world, particularly in North America, Argentina, and Australia, which increased the world’s wheat supplies during the formation of a global market in agricultural goods. Third, and perhaps most important, Malthus’s analysis of fertility was deeply flawed. During the Industrial Revolution, total fertility rates declined and family sizes decreased. Thus, contrary to his expectation, humans are not mere prisoners of their genes and the birth rate is a socially constructed phenomenon, not a biological destiny.
In the 1960s, when the world experienced average population growth rates in excess of 2.6% annually, Malthusianism underwent a revival in the form of neo-Malthusianism. Neo-Malthusians acknowledged the errors that Malthus made but maintained that while he may have been wrong in the short run, much of his argument was correct in the long run. In keeping with the growing environmental movement of the times, neo-Malthusians also added an ecological twist to Malthus’s original argument. The most famous expression of neo-Malthusian thought was the Club of Rome, an international organization of policy makers, business executives, scholars, and others concerned with the fate of the planet. The Club of Rome funded a famous study of the planet’s future, published as The Limits to Growth (1972), which modeled the earth’s population growth, economic expansion and resource consumption, and energy and environmental impacts. It concluded that the rapid population and economic growth rates of the post–World War II boom could not be sustained indefinitely and that ultimately there would be profound worldwide economic, environmental, and demographic crises. Much of this argument was framed in terms of the exhaustion of nonrenewable resources such as oil and ecological catastrophe. Indeed, the last half century has indeed witnessed massive degradation of ecosystems around the world, and some resources such as petroleum have already passed their peak production year. Unlike Malthus, neo-Malthusians advocated sharply curtailing population growth through the use of birth control and had an important impact on international programs promoting contraceptives and family planning, such as the Peace Corps and Agency for International Development.
While neo-Malthusianism retains a credibility that the original Malthusian doctrine does not, it, too, suffered from a simplistic understanding of how resources are produced (e.g., when the price of oil rises, corporations find more oil). Blaming overpopulation for all the world’s problems is simplistic, skips over the historical forces such as colonialism that generate poverty, and ignores major issues such as government policy. For example, is the crowding of a train in a developing country the result of overpopulation or the lack of investment in transportation services? In addition, family-planning programs in the developing world have often failed to live up to expectations, often for the simple reason that simply advocating contraception to curb population growth ignores the fundamental economic reasons why people in impoverished countries have large families and many children. In short, whatever its merits, neo-Malthusianism must be viewed in light of other models of population growth that originate from different premises and often arrive at different conclusions.
Case Study
Population and Land Degradation
Human population growth is a leading force in global land degradation and environmental change. Global population increased from 5 billion in 1987 to 6.9 billion in 2010, an average annual growth rate of 1.4%, with Africa recording particularly high growth rates. This population increase, together with the gap between rich and poor and discrepancies in income-earning opportunities, has increased the demand for food and energy, putting pressure on available environmental resources such as fresh water, fisheries, agricultural land, and forests.
Population growth has resulted in increased demand for agricultural productivity, higher incomes, and changes in consumption patterns. Inequitable land distribution, a legacy of colonialism and political conflicts, has exacerbated the problem. Land degradation is especially acute in developing countries where a significant portion of the population is dependent on subsistence farming.
Poverty also is a major cause of land degradation, with population growth and poverty reinforcing each other to bring about a spiral of decline in soil fertility. Neo-Malthusians warn that population growth will outstrip the natural supplies of food, water, and shelter. The neo-Malthusian theory further regards population growth and the environment to be in conflict, with the quest for food security coming at huge inevitable environmental costs, ultimately leading to an escalation in land degradation, a decline in agricultural productivity, and greater food insecurity. The argument effectively states that the world would literally run out of food unless drastic steps are taken to protect the environment from people. Simultaneously, common property tenure systems also exacerbate the utilization of common property resources, leading to overutilization and degradation from elements such as overgrazing. People (especially the rural poor) have been blamed for misusing the resources at their disposal for short-term gains. Such land misuse is accentuated by the coping strategies employed in the face of food insecurity.
In contrast to the Malthusian view, food security and the environment are considered to be complementary and interdependent, with a healthy natural resource base providing food security. It is argued that population increase and income growth drive technological inventions such as agricultural intensification to solve food production constraints, thus achieving environmental and economical sustainability. It is further argued that the neo-Malthusian perception disregards the potential for economic development within sustainable environments when confronted with rapid population growth and assumes that agro-ecological zones have limited carrying capacities. Population growth, food security and a healthy natural resource base are viewed as interdependent and mutually reinforcing for positive gain to both.
Land degradation occurs through various processes, including loss of vegetation, soil erosion leading to loss of fertility, declining soil biodiversity, and soil compaction, which leads to reduced infiltration and increased runoff salinity. Other effects of land degradation processes include water pollution, siltation of watercourses and reservoirs, and loss of animal and plant diversity, leading to loss of ecological functions. Land degradation is often viewed as a trigger for disasters such as landslides.
Land-use change has both negative and positive effects on human well-being and on the provision of ecosystem services. Positive changes include more food and forestry products that have resulted in increased income and secure livelihoods. Negative changes include biodiversity loss and disturbances of biophysical cycles (e.g., water and nutrients) that impinge on human welfare in many regions. Soil erosion, particularly in the rural regions where the majority of the population resides, may reduce agricultural yields, resulting in increased food insecurity, famine, and poverty, as well as forced migration, especially for impoverished people and countries. Demand for more food production contributes to overexploitation of good agricultural soil and expansion into wooded and environmentally marginal areas that are susceptible to degradation. Processes such as clearing of woodlands, logging, firewood collection, and charcoal production lead to deforestation. The highest rates of deforestation occur in areas where hunger is prevalent. Land degradation consequences can induce declines in forest products and wild foods and worsen levels of poverty and malnutrition, especially since these resources are harvested often as coping strategies in the face of droughts and floods.
