Peter McDonald has been Head of the Demography and Sociology Program in the Research School of Social Sciences of the Australian National University since 1996. ANU Demography is one of the oldest and largest centres for the study of demography in the world. He is also Co-Director of the Australian Centre for Population Research. His international research is focused on explanations of low fertility rates in advanced countries and the implications of population dynamics for ageing and the labour force. With Rebecca Kippen, he has written widely on population dynamics in Australia. With Siew-Ean Khoo, he has co-edited the recent UNSW Press volume, The Transformation of Australia's Population, 1970-2030. He is Chair of Panel A of the Academy of the Social Sciences in Australia and is a Council Member and Chair of the Committee on Scientific Activities of the International Union for the Scientific Study of Population.

Demography and interdisciplinarity
by Peter McDonald

Session 5: Questions/discussion

In the late 1950s when the United Nations first became involved in making world population projections, it projected that the world's population in 2000 would be 6.3 billion. The actual result was 6.1 billion meaning that the error in the late 1950s projection was only 3 per cent. Furthermore, over the period since the late 1950s, the UN medium projections for the year 2000 never changed very much from the level projected in the late 1950s. Remarkably accurate one might say.

The accuracy of the global estimate stems in large measure from the nature of population dynamics, in particular, from what demographers call 'population momentum'. A considerable proportion of future population change is built into the current age distribution of the population. Much of the growth of the world's population between 1960 and 2000 was due to the age distributions already known in 1960. Population momentum is like an aircraft carrier at full speed- it takes a long time to slow down. However, at the global level in the past 40 years, both births rates and death rates have fallen faster than was projected around 1960, tending to cancel each other out – a second reason for the apparent accuracy of the late 1950s projections.

While the 2000 world population projected from the late 1950s was very accurate, this is not the case with projections of the 2050 population from 1960. Medium projections of the 2050 population made around 1960 were as high as 17 billion but have been progressively revised downwards ever since. The current UN medium projection for 2050 is 8.9 billion, almost half the 1960s projections. Indeed, the UN is now talking about the world reaching a maximum population of 9.2 billion in 2075 whereafter world population would fall.

What caused this dramatic change in the trajectory of world population? In demographic terms, it was caused by falls in fertility rates around the world that were far faster than was ever envisaged in the 1950s. Falls in fertility have two impacts. In the short term, they reduce the number of births and hence the size of the population. In the 1960-2000 period, mortality rates also fell faster than envisaged in 1960 producing something of a compensatory effect on total numbers by 2000. But, in the long term, and more importantly, the rapid falls in fertility through their impact on age structure greatly reduced the future impact of population momentum. Among the demographic variables, it is fertility that has the largest impact on population momentum. Thus, while the total world population in 2000 was projected very accurately from 1960 onwards, the 2000 world age distribution was considerably older than had been projected in 1960.

It is an understanding of population dynamics, the way in which fertility, mortality and migration interact with age structures, that the discipline of demography brings to discussions of population and environment. Population is not a number that grows exponentially and inexorably. It can, but it almost never does.

Australia's rate of natural increase is now 0.6 per cent per annum but we know that with no change in fertility and falling rates of mortality, this rate will fall below zero sometime after 2030 – because this change is built into Australia's current age structure: a negative rather than a positive population momentum.

The rapid falls in fertility that have occurred over the past 40 years in developing countries did not just happen. In almost all cases, they were at least partly the result of deliberate government policy, most particularly, government-supported family planning programs. What gave rise to this policy direction?

The initial impetus came from demographers who showed that the existing population dynamics implied huge future populations for the 21st century. While there was an argument from pure Malthusian logic that these futures were impossible, the vital intellectual association was between demographers and development economists. They produced an argument that economic development and human progress would be held back if fertility rates continued to be high. One of the more important contemporary syntheses of the argument is this paper: 'The Economic Effect of Declining Fertility in Less Developed Countries', written by Gavin Jones in 1969. The report concludes:

This argument has been assaulted over and over since the 1960s, most particularly in the 1970s. Ironically, I think there is an argument that the 'limits to growth' debate that was raised in the 1970s actually contributed to the assault upon the argument that population control was good for development. The argument relied upon the carrot that economic growth would follow from population control. The 'limits to growth' debate said no more growth anywhere and spurred economists like Julian Simon to argue against the relationship between population and development. At the same time, the international population debate was about which came first, development or population control (development is the best contraceptive). Since the 1970s, economists in general have become somewhat agnostic on the benefits of population control for future development (yes, in the short term but not necessarily in the long term – about 20 years for economists). However, demographers generally stayed with the earlier argument – looking to a long term than was longer than the economists looked to.

Importantly in the end, the argument was widely accepted by people who mattered (politicians and planning officials in developing countries and politicians and bureaucrats in developed countries and international agencies).

Action followed through concerted efforts on the part of international and national agencies and several university-based programs. Beyond lobby groups, some of the important players were the Population Council, the Ford Foundation, USAID, UNFPA, the Universities of Chicago, Princeton, Berkeley, Michigan and our own Australian National University – as recognised through Jack Caldwell being awarded the UN Population Award. Demographers were working in planning agencies in developing countries, in newly-created family planning agencies, in central statistical offices and in universities in developing countries. Most of the prominent Australian demographers today spent much of their career working in this enterprise. I spent the 1970s working in and on Indonesia.

Training of developing country demographers and economists was a crucial component. In the past 40 years, ANU alone has trained some 300-400 developing country demographers at the graduate level. While foreign involvement may have been important at the beginning and often continued to be important in the backroom logistics, in most countries, the agenda was rapidly captured by national governments and national authorities and adopted as their own. Those trained overseas had a very strong role in this process. This accelerated the success of the fertility control agenda because policy approaches were adopted at the local level that were 'culturally appropriate' though not necessarily always to our taste.

Availability of good statistical information was another vital component. Considerable international funding was directed to the taking of scientific censuses in developing countries. Then, funding was provided for ad hoc fertility and family planning surveys. In the 1970s, a systematic series of surveys was commenced: the World Fertility Survey – and these have been followed up by what is now a relatively regular series in many countries of Demographic and Health Surveys.

The agenda was criticised as a capitalist plot (and to some extent it was), as immoral (forced sterilisations in India, social coercion in Indonesia, increased access to clinical abortions, China's one-child policy), as bad economics (growth is good and economic growth is driven by population growth) or as bad social policy (development is the best contraceptive) but the agenda rolled on mainly because, in the end, it was accepted as good planning by the leaders and planners in developing countries. The outcome is the dramatic success we see today: the prospect of an end to world population growth at a level way below what would have been the case without this concerted effort. The end justifies the means? You be the judge. Thailand versus Philippines; India versus Pakistan?

What has this all got to do with population and environment? First, the success of these efforts has undoubtedly improved the environmental future of the world. However, the main point that I am making is that powerful multidisciplinary alliances are possible. Today, the population agenda is much more mixed and maybe more complicated. The effort to bring down fertility rates in many developing countries must be continued – and we are now left with some of the more difficult cases. At the same time, the latest report on world population policies indicates that nearly half of all developed countries now view their population growth rate as too low and almost 40 per cent have adopted policies to raise their population growth. Again , the power of population momentum is an important part of the story but this time it is a momentum for population decline and, more immediately, massive falls in labour supply arising from age structures that are the result of 25 years of very low fertility rates. Over the next 40 years, Japan is facing a fall in its labour supply of 20 million workers. For Germany the number is 12 million, for Italy 11 million and for Spain 7 million. This is a serious economic issue for these countries that cannot be dismissed with a simplistic – 'they'll be better off if they have fewer people'. Thirty-nine countries now consider that their fertility rate is too low. Australia, for the first time in 30 years of reporting to the UN, has a fertility policy – to maintain fertility at its present level. Good policy in my view.

At the same time as we have these conflicting national population trends, global environmental issues, particularly climate change, have emerged to produce serious concerns. There have always been local-level environmental issues associated with population growth and these continue and are changing in nature: vast mega cities of 25 million people or more; deforestation; soil degradation; water shortages. The rapid economic development of China combined with its huge population is beginning to present enormous challenges for resource supply and depletion. Thus, the population-economic development argument now has a very distinct and important environmental dimension.

There have always been demographers who have had a strong interest in environmental issues but there was a quantum leap in the quality of population-environmental studies and linkages in the 1990s: Joel Cohen's, How Many People Can the Earth Support; Lindahl-Kiessling and Landberg's Population, Economic Development and Environment; the modelling work undertaken by Keyfitz, Lutz, Sanderson and MacKellar at the International Institute for Applied Systems Analysis in Austria; the Joint Statement on World Population by 58 of the World's Scientific Academies; McMichael et al.'s Climate Change and Human Health. The population and environment issue has been well covered by the leading demographic journal, Population and Development Review. More recently, the International Union for the Scientific Study of Population has created a network, the Population and Environment Research Network, that provides access to a very wide range of bibliographic material and holds cyber seminars – there is one running as we speak. IUSSP jointly with other organisations has produced a Statement on Population and Sustainable Development. The International Population Conference organised by IUSSP and to be held in France in 2005 has sessions on: population and environment; migration and the environment, urbanisation, environment and development; population, environment and development; and climate, population and health. The site is now open for paper submissions.

Overall, I believe that there is lots of room for optimism that good multidisciplinary work on population, economic development and environment will proceed in the future – so long as it is undertaken in an atmosphere of moderation and compromise.