Joel Cohen: An Introduction to Demography (Malthus Miffed: Are People the Problem?) | Big Think

Joel Cohen argues for the importance of demography, especially for the younger generation, as they will face unprecedented challenges related to an aging global population and increased migration. Understanding demography provides the tools to comprehend the arguments behind these complex issues as a citizen, taxpayer, and voter.

Cohen highlights critical global problems: one billion people are chronically hungry, another billion live in slums lacking basic infrastructure, nearly a billion are illiterate (two-thirds of whom are women), and over 200 million women lack access to desired contraception, leading to many unintended pregnancies. These are presented as direct examples of urgent population problems.

Demography studies populations of humans, non-human species, and even non-living objects, using quantitative data and mathematical models to analyze past, present, and future trends. It is a central subject connected to economics, human well-being, environmental health, and culture.

Since the invention of agriculture, the human population has grown 1,000-fold, from seven million to nearly seven billion, while the Earth's size remains constant. This rapid growth, especially in the last 200 years, raises concerns about human impact on the planet and the well-being of all species. Historically, doubling times for the population have drastically shortened, from 16 centuries to just 44 years. However, around 1965, the population growth rate began to decline.

Since 1950, global fertility rates have halved from five children per woman to about 2.5, a swift voluntary change, though less so in Sub-Saharan Africa. Cohen introduces the concept of 'replacement level fertility,' explaining it using a bathtub analogy: 2.1 children per woman keeps the population steady. Since 2003, more than half of humanity now lives in countries at or below replacement level fertility, a historic first, yet the global average is still 2.5, indicating continued growth.

Using population pyramids, Cohen illustrates the stark contrast between rich and poor countries. Rich countries have a slender column shape, indicating a more even age distribution, while poor countries have a wide base, signifying a large young population. This means developing nations face immense challenges in education and health, and possess a much larger potential military force. Rapid demographic growth is concentrated in the poorest countries, where 3.5 billion people live on less than $2 a day. The economic inequality means those with the highest need for reproductive healthcare have the least access. Cohen argues that the rich world benefits from the poor world's development through economic exchange and public health, as diseases cross borders regardless of wealth.

Cohen projects four certainties for the world by 2050: a larger population, slower growth, an older demographic, and increased urbanization. Population projections vary significantly based on fertility rates; maintaining current rates could lead to 11 billion people by 2050, while declining fertility could stabilize it at 9.1 billion. Choices made now regarding women's education, access to credit, reproductive healthcare, and delaying marriage will significantly impact future population size and quality of life. The focus should be on the quality of children, not just quantity.

The world's population growth will slow, from 76 million annually today to an projected 31 million by 2050 (in poor countries, growth will be 32 million, while rich countries will see a decline of 1 million). Over 50 countries already experience population decline. This slowing is linked to a shift from quantity to quality in childbearing, as urbanization, education, and wealth lead to greater investment in fewer children. By 2050, the elderly population (three times the number of children) will outnumber the young for the first time in human history. This aging trend will increase demand for utilities and healthcare, posing challenges to a shrinking workforce. Investment in youth education is critical to ensure healthier, more productive elderly populations.

Urbanization is a major future trend. While half the world was rural and half urban in 2000, by 2050, the rural population will remain at three billion, but the urban population will double to six billion, with all this growth in poor countries. This requires building a city of one million people every five days. Underinvestment can lead to four billion people living in slums, but strategic investment can reduce them. Urbanization brings both hazards (coastal cities vulnerable to natural disasters, infectious diseases, and attacks) and positive aspects: lower fertility rates (children become liabilities instead of assets), higher contraception usage, concentrated economic productivity (80% of global GDP), and potential for energy efficiency (e.g., lower CO2 emissions in dense cities like New York). Urban growth poses a challenge to food supply, as cities often occupy prime arable land; future choices will determine whether cities expand or increase density.

Cohen presents three categories of solutions: 'bigger pie' (technology for increased production), 'fewer forks' (contraception to reduce population growth and consumption), and 'better manners' (eliminating violence and inequities). He advocates for all three, stressing the importance of high-quality education for all children (boys and girls) for 10-12 years, preceded by adequate nutrition for pregnant women and infants. Currently, 925 million people are chronically undernourished globally, and 17.4 million US households experienced food insecurity in 2009. Despite growing enough food, less than half of it directly feeds people; much is used for biofuels, animal feed, or industrial purposes. Hunger is 'economically invisible' because the very poor cannot participate in markets. Cohen's formula for global problem-solving includes: eliminating unintended pregnancies, educating all children, opening credit and markets for small (often female) farmers, eliminating perverse subsidies, raising poor incomes, protecting farmland, internalizing agricultural environmental costs, promoting healthy diets, and funding agricultural research for crops important in poor countries.

Cohen emphasizes that population, economics, environment, and culture are deeply intertwined. He warns against simplistic solutions, such as relying solely on contraception, market forces, legal frameworks, or environmentalism alone. All aspects must work together, recognizing that human well-being and environmental health are mutually dependent, particularly for poor rural populations. He encourages the study of demography for its analytical tools, mental engagement, and its capacity to empower individuals to intervene wisely and effectively to improve the well-being of all, including other species. He concludes with an appeal to immediate action for the greater good.