What’s another 4 billion people? A new challenge

Expert to discuss how population is likely to grow even as birth-rates drop

As the Earth accommodates the next 4 billion humans, chances are that the demographic issues will differ from the last population increase of that magnitude—between 1960 and 2010.

Key among the differences is that population growth is expected to be driven primarily by an increasing longevity rather than by new births. So contends David Lam, professor and chair of the economics department at the University of Michigan and a research professor at that institution’s Population Studies Center.



Lam will give a presentation on the topic Monday, March 2, from 3 to 4:30 p.m. in CU-Boulder’s Institute of Behavioral Science Room 155B. His talk is titled: “Four Billion More People but Fewer Children: The Peculiar Demography of the 21st century and its Economic Implications.”

Lam’s presentation is part of the Jane Menken Annual Distinguished Lecture Series, named after the longtime director of IBS and member of the institute’s CU Population Center.

The United Nations projects that world population will increase by 4 billion people—from 7 billion to 11 billion—between 2010 and 2100. Can the world support another 4 billion more people?

To answer this question, Lam argues, it is useful to consider the period between 1960 and 2010, when the world also added 4 billion people. He notes important demographic differences between 21st-century population growth and 20th-century growth.

Lam will discuss how it is possible to add 4 billion people to the world without adding any more children. It will also discuss the economic implications of this unusual pattern of population growth.One of the most “intriguing” is that the number of children age 0-4 in 2100 is projected to be smaller than the number of children in 2010, in spite of the additional 4 billion people, he observes.

While 20th-century population growth was dominated by growth in the number of children, 21st-century population growth will be dominated by growth of older age groups.

Lam’s lecture will discuss how it is possible to add 4 billion people to the world without adding any more children. It will also discuss the economic implications of this unusual pattern of population growth.

While earlier population growth led to increased demand for schools and put pressure on youth unemployment, 21st century population growth will put pressure on the labor market for older workers and on support systems for the elderly, he says.

Lam will also discuss large regional differences in these patterns: while population growth will slow dramatically in most regions, sub-Saharan Africa will continue to experience rapid population growth and increasing numbers of children and youth.

Africa will also experience an increase in the proportion of its population in working ages, however, potentially an important positive factor in African economic growth.

The Jane Menken Annual Distinguished Lecture Series is sponsored by the CU Population Center.

Feb. 19, 2015