HIST 3797: Population Theory

Malthus, Marx, and Boserup

Mercantilist theory (17th, 18th c):

• Population growth a good thing• Social good measured by the wealth and power

of the nation state• Population the source of public revenues, larger

GNP, military might, peopling colonies• “A numerous and increasing population was the

most important symptom of wealth; it was the chief cause of wealth; it was wealth itself—the greatest asset for any nation to have.”

Thomas Malthus, Essay on Population (1798)

• Social good measured by the well-being of the people, including the laboring classes/poor

• Poverty was the natural consequence of population growth

• Malthus’s “law” of population: population grows geometrically; food and resources grow arithmetically

Malthusian model:

• Food is the primary resource; food scarcity increases mortality, reduces population

• Law of diminishing returns: cultivating new land, or more intensely, adds smaller increment to production for each unit of labor/land

• Productivity gains from innovation cancelled out by more pop growth

• As population increases, food prices rise (excess demand), wages fall (excess supply), mortality increases

Two types of checks to population

• Positive checks– anything that increases mortality (war, disease, famine, poor living standards) and kills off excess population

• Preventive checks- abstinence, delayed marriage and non-marriage (“moral restraint”) that limit the number of children born

• Preventive checks superior (less human misery) but probably unattainable (due to human weakness)

• What’s missing?

Malthus’s theory reflects his times

• End of 18th c: population was increasing, wages were falling

• Assumes primarily agricultural society with limited technological innovation (at the cusp of the Industrial Revolution), where laborers spent most income on food (bread)

• Fertility levels depended on marriage age and frequency; fertility control within marriage not generally “within the calculus of conscious choice”

Malthus’s theory became standard argument against social reform

• Anything that raises the income of the poor (e.g., poor law payments) would raise the birth rate

• Number of the poor would then increase until there were so many that incomes would fall and mortality would increase

• Hence, it’s impossible to raise the income of the poor; don’t try

• This argument was very popular with the rich

Malthus’s contribution to population theory generally

• Lays out system of population and economic dynamics (fertility vs. mortality, individual well-being and the broader economy)

• Sets forth premise that rising population reduces living standards, due to diminishing returns

• Pessimistic about science and innovation solving problems from increasing population

• Neo-Malthusians: Adopt Malthus’s pessimistic perspective about “overpopulation,” see birth control as preventive check

Marxist Theory (mid-19th century, Karl Marx and Friedrich Engels)

• Criticized Malthus• “Every stage of development” (economic

system) has its own law of population• Pressure of population is against “the means of

employment,” not the means of subsistence• “It is capitalist accumulation itself that produces .

. . A relatively redundant population of labourers”• An over-simplified example

Marxist population theory, cont.

• Assumes different law of population under socialism; centralizing the mean of production for the general good does away with “surplus population” and poverty

• After English Industrial Revolution, so more optimistic about “science, the progress of which is just as limitless and at least as rapid as that of population”

• In practice, later, Communist regimes saw population planning (like economic planning) an appropriate task for the State (e.g., China, Romania)

• Marx’s general contribution: Distribution of resources among the population matters, not just total population and production levels

Boserup, et. al: Population pressure spurs technological change

• Optimistic perspective: “Demographic growth stimulates human ingenuity so as to cancel and reverse the disadvantages imposed by limited resources. A larger population generates economies of scale and more product and surplus, and these in turn support technological progress.”

Boserup’s argument (1981):Population growth has stimulated technological progress. Early in human history, growing needs of numbers of people promoted

the use of fire, the domestication of animals, the storage of food and the development of agriculture, a productive system supporting much larger populations than hunting and gathering.

In the following millennia, population growth stimulated improvements in agricultural productivity, via both technical innovations and reorganization of societies.

More recently, population growth provided the concentrations of labor and the supply of ingenuity to spur the industrial revolution and the development of modern societies, with their high levels of employment in the production of services.

Some work of this type reverses traditional causal reasoning:

Traditional economic argument: Development of new technology allows population to increase.

Newly-invented technology is self-evidently superior.

Once adopted, this superior technology supports a larger population.

Causality: Invention-> pop change.

New argument: Wide range of possible

technological solutions.Increased population pressure

encourages adoption of more labor-intensive techniques.

Decreased population pressure encourages adoption of less labor-intensive techniques.

Causality: Pop change->Technological change.

Example: Agricultural systems

• Low yield, low labor intensity: Slash and burn agriculture: Trees cut and burned; ash fertilizes the soil; pointed stick used for planting; land cultivated for 1-2 years, left fallow for 20 years. Productivity per hour worked is high, but only feeds small pop. w/in fixed area.

• High yield, high labor intensity: Land cleared, plowed, fertilized, weeded, irrigated; livestock maintained; annual cultivation, with crop rotation. Productivity per hour worked is low, more hours worked, but feeds a larger pop. w/in fixed area.

• System adopted depends on population pressure, may revert back to less labor intensive (Europe after Black Plague)

Example: From hunting and gathering to cultivation (Cohen)

• Agriculture consists of practices and techniques known to hunter-gatherers, but usually not practiced because unnecessary

• Hunting and gathering supplies more varied, possibly more nutritious diet, with few hours of labor/day

• Agricultural techniques adopted due to population pressure; more monotonous, possibly less nutritious diet, with longer work hours—but feeds more people in a given area (10-100 times more people per acre)

Positive Feedback Cycle (Diamond)

• Gradual rise in numbers impelled people to obtain more food, through agriculture

• Food producers generally sedentary rather than nomadic. Sedentary life supported shorter birth intervals, reduced “cost” of children, leading to more pop growth.

• Note: Hunting and gathering co-existed with cultivation in many societies.

Livi-Bacci: 3 historical responses to population pressure

• The occupation of uninhabited or sparsely populated regions

• Land transformation and reclamation (e.g., draining of swamps for cultivation)

• External expansion: emigration and colonization

Advantages of larger population

• Encourages division of labor, leading to more efficient production of goods

• Allows economies of scale, development of infrastructure (e.g., irrigation systems, transportation networks)

• Supports the growth of cities, more complex societies

• More people =s more potential inventors of new technology (Simon)

Current Population Theorists: Optimists and Pessimists

• Optimists: Some economists assume that technological innovations will solve current and future problems from pop growth (e.g., development of substitutes for scarce resources, broader use of contraception)

• Pessimists: Many ecologists argue that growing population threatens resources that can’t be replaced (e.g., climate change)

• Some predict future difficulty in increasing food production; 1/7th of world population suffers from hunger and malnutrition (U.N. estimate)

• Some solutions available to historical populations not feasible today