The Floating University

Malthus Miffed: Are People the Problem, the Solution, or Both? 

An Introduction to Demography and Populations Study Through an Examination of the World's Population.

JOEL COHEN, Abby Rockefeller Mauzé Professor of Populations, Rockefeller University, Mathematical Biologist, Columbia University

Lesson Overview

Why study demography? You will be growing up in the generation where the baby boomers are going into retirement and dying. You will face problems in the aging of the population that have never been faced before. Billions of people will live in mega slums without access to clean water or medical care. In his lecture, Malthus Miffed: Are People the Problem, the Solution, or Both? An Introduction to Demography and Populations Study Through an Examination of the World’s Population, Professor Joel Cohen will show how demography can provide answers to these life or death questions as the world's human population swells and resources dwindle.

Professor Cohen first asks and answers the question, “How did humans grow from small populations on the African savannah to almost seven billion people?” After holding steady for thousands of years, the world population exploded after 1800, more than tripling in 200 years. And while the rate of population growth is slowing down, Cohen shows how high birth rates in poor countries are turning societies on their head and leading to explosive problems in the future. Can we prevent an outcome where rich western countries are in permanent population decline while cities in Africa, South America, and Asia swell into massively overcrowded slums with no access to education, healthcare, or hope? Cohen applies demography to this pressing question with fascinating results.


  • Course Pack: Joel E. Cohen, How Many People Can the Earth Support? W. W. Norton, New York. (1995) (pp. 25–31; pp. 97-105; pp. 356–364)
  • Course Pack: Massimo, Livi-Bacci, A Concise History of World Population: An Introduction to Population Processes. (3rd rev. ed. Blackwell Publishers, Cambridge MA and Oxford UK. 2001) (Section 5.4, pp. 147–154)
  • Online: Joseph A. McFalls Jr, Population: A Lively Introduction. Population Bulletin. 62(1). 2007. Link:
  • Online: H. Charles J. Godfray, John R. Beddington, Ian R. Crute, Lawrence Haddad, David Lawrence, James F. Muir, Jules Pretty, Sherman Robinson & Camilla Toulmin, Philosophical Transactions of the Royal Society (London) Theme issue “Food Security: Feeding the World in 2050” September 27, 2010; 365 (1554). Link:

Discussion Questions

(1.) How do populations affect economies, the environment (land, marine and fresh water, the atmosphere, other living species), and culture (including law and politics)? Vice versa, how are populations affected by economics, the environment, and culture? Give concrete examples based on your personal observations, not what you read or hear in news sources. Are the interactions (two-way causal interactions) simple and well understood? 

(2.) How could, should, or will your knowledge of the past and prospects of global human population (its size, spatial distribution, age structure, health, education, and household structure) affect your personal demographic choices about marriage, divorce, childbearing, urban or rural location, and healthy behavior?

(3.) How could the massive global aging of the population affect your personal future? What could be done to prepare future cities for an aging population?

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About Joel Cohen

Joel Cohen, PhD, DrPH, is a mathematical biologist and a professor of populations. His research deals with the demography, ecology, epidemiology, and social organization of human and non-human populations and with mathematical concepts useful in these fields. Dr. Cohen is a MacArthur Fellow, member of the National Academy of Sciences, and a member of the Board of Trustees of the Population Reference Bureau. He shared the Tyler Prize for Environmental Achievement from the University of Southern California in 1999 and earned the Fred L. Soper Award for Excellence in Health Literature from the Pan American Health and Education Foundation in 1998 for his work on Chagas disease. Dr. Cohen is currently the Abby Rockefeller Mauzé Professor of Populations at the Rockefeller University in New York City and at the Earth Institute of Columbia University.