(June 2002) A March meeting of demographers at the United Nations captured headlines proclaiming “Population Decline in Sight,” “Shrinking World,” and “Population Boom a Bust.” Although more attention to population trends is welcome news, the media’s focus on a single aspect of the UN’s deliberations produced stories at odds with what many participants took away from the meeting.

What happened at the Expert Group Meeting on Completing the Fertility Transition, the third in a series on future fertility trends, was that population experts endorsed a proposal by the UN Population Division to accommodate fertility levels below the two-child-per-couple replacement level in the division’s 2002 revision of its world population estimates and projections. Endorsement came after examination of the fertility prospects for a large group of less developed countries, those with a total fertility rate less than 5 children per woman, but more than 2.1, or the “intermediate-fertility” countries. This group includes Bangladesh, India, Indonesia, Iran, Mexico, and Vietnam.

This step means the UN will consider fine-tuning its assumptions. It is also considering projecting to 2075. This kind of tweaking is done regularly (see table below).

Target Fertility Assumptions Used in UN Projections for 2045–2050

Year of Projection More Developed Countries Less Developed Countries
1994 2.08 2.10
1996 2.06 2.10
1998 1.82 2.06
2000 1.92 2.17

Note: Rates are total fertility rates, based on average number of children per woman per country.
Source: UN Population Division.

Back in 1997, the Population Division considered developments in the low-fertility countries, primarily those of Europe. The conclusion of that conference marked a wide-ranging departure from what had been the UN’s long-range assumption about fertility for most countries, but not all — that it would either rise or fall to the replacement level of about 2.1 children per woman. While such an assumption may at first appear arbitrary, it had, in years past, several attractive features. For one, a long-term assumption of replacement level ensures zero population growth, avoiding individual assumptions about which countries might decline in size and which might not. It also provided a readily understood benchmark for the medium variant, the two-child family. (For comparison purposes, the UN also produces high and low variants, which assume long-term fertility above and below replacement, respectively.)

Over time, it became obvious that a rise to replacement fertility in the very low-fertility countries of Europe was, in fact, quite unlikely. The individual countries did not assume that in their own national projections. So, the Population Division’s 1998 series dropped the general assumption of a long-run return to replacement-level fertility by 2050.

More recently, differing patterns have become evident in the fertility trends of less developed countries. Just as more developed countries were projected to rise to replacement in the medium series, the less developed countries were projected to decline to it and then stabilize at that level. However, it is now clear that fertility-decline patterns are far more likely to exhibit wide disparities in less developed countries. Some less developed countries have already completed the transition to low fertility. Others have seen their rate decline to a middle level and then stall. Still others have shown no sign of fertility decrease whatsoever. That last group was the subject of the second UN conference in this series held in July 2001, the Workshop on Prospects for Fertility Decline in High Fertility Countries (see Population Today, October 2001).

The next round of UN projections, expected out in the first quarter of 2003, will incorporate a new “floor” for fertility in most less developed countries. Rather than assume a decline to a long-term total fertility rate of 2.1, 1.9 will now be the ultimate value — that is, below-replacement fertility. But the real issue is the path taken to that value. It could occur before 2050 (or even 2075 if the projections are run out to that year) or well after. There could be a “plateau” as fertility decline slows on approach to a lower value.

At the March meeting, there was consensus that below-replacement fertility is likely to occur in some less developed countries at some point in the future, but that, in many cases, that point is too far away to foresee accurately. Nevertheless, population decline is not in sight, given the young age structure of less developed countries and their persistent high birth rates.

One conclusion from the conference that may stand out is that population projections must be adjusted as childbearing patterns themselves change. Thus, a population projection for a high-fertility country such as Niger may now assume that fertility remains high for a much longer period than was assumed in the past, while a projection for Brazil may now assume that fertility decline moves rather smoothly below the replacement level. If the UN population projections now appear more complex, they are only reflecting the changing world for which they are made.

Carl Haub holds the Conrad Taeuber Chair of Population Information at PRB. 

For More Information

The agenda, list of participants, and background papers for the Expert Group Meeting are available on the website of the UN Population Division: www.un.org/esa/population/publications/completingfertility/

The UN Population Division has released version 3.0 of the Population, Resources, Environment and Development Databank (PRED Bank). PRED Bank, available on CD-ROM, brings together data series on population; labor force participation; education; economic and social development; and land, water, and energy use. The 131 variables on the CD-ROM include regional, subregional, and national data for 228 countries and regions.
The CD-ROM is available for US$75. It can be purchased by check or international money order in U.S. dollars drawn on a U.S. bank, payable to the UN Population Division. Interested institutions in less developed countries may receive one free copy of the CD-ROM by submitting a request printed on their letterhead paper. Correspondence should be addressed to Joseph Chamie, Director, Population Division, Room DC2-1950, United Nations, New York, NY 10017, USA, or faxed to 212/963-2147.