Joel E. Cohen, 1999 Tyler Laureate
Joel E. Cohen, Ph.D., is the Abby Rockefeller Mauze Professor of Populations
at The Rockefeller University in New York. He has made important contributions
to the understanding of food webs in natural and human-made ecosystems and
developed realistic, unbiased models of population growth and the carrying
capacity of earth.
Cohen's studies of human population dynamics began in the 1970s. He observed that neither birth rates nor death rates were constant over time and developed an important mathematical model representing these random fluctuations. This work laid the foundation for more realistic assessments of the uncertainty of future human population size and age composition. His 1995 book "How Many People Can the Earth Support?" has raised the level of sophistication of public discussions on population. Cohen's work on food webs was the first to call attention to regularities in the feeding relationships in ecological communities and to develop quantitative models to explain these regularities. This work laid the foundation for the development of food-web ecology over the last 20 years.
His work on the infectious diseases of humans has focused on some neglected killers (malaria, schistosomiasis, and Chagas disease) of disadvantaged people in tropical countries and on the interactions of diseases with demography, economics, and the environment. For example, his studies on the household ecology of Chagas disease in Argentina have generated knowledge that could make it possible for families to prevent this incurable disease, which currently afflicts up to 20 million people in Latin America. As director of the Board of the Societal Institute of the Mathematical Sciences, a non-profit organization devoted to bringing mathematical methods to bear on social problems, Cohen helped improve monitoring of air and water quality, less-polluting energy production and more effective AIDS surveillance, modeling and prevention.