Population change over time

There have been various attempts by geographers, sociologists, economists and others to consolidate the processes bringing about change in populations through the use of theories and models. Two of these have made considerable impacts on approaches to our understanding of the process of population change: Malthus’s ‘Essay on the Principle of Population’ and the ‘Demographic Transition model’.

Malthus One early demographer was Englishman Thomas Malthus (1766–1834) who wrote ‘Essay on the Principle of Population’ in 1798. At this time England’s Industrial Revolution was changing the structure of the population. It was becoming increasingly urban, death rates were starting to fall but the birth rates remained high. It seemed as if the population was growing out of control.

Malthus hypothesised that while the world’s population would grow exponentially (2, 4, 8, 16, 32…), food production would only increase arithmetically (2, 4, 6, 8, 10…), over the same period.

Consequently there would be a gap between the ability of an area to support a population and the size of the population wanting to live there. In other words, population growth would eventually outstrip the resources needed to support the population. Malthus’ arguments were strongly critical of Britain’s working class for their rapid reproduction, which he believed would lead to widespread poverty. Charity for this section of the population would only encourage further reproduction and eventually more poverty

Malthus believed there was a solution, or rather a series of situations that could check population growth: couples should practise abstinence, delaying marriage and sex until they could afford to raise children

marriage between couples of extreme poverty or with ‘social defects’ should be restricted a population unable to feed itself would be subject to starvation, disease and or war. These events could help reduce the size of a population to more sustainable levels.

Malthus’s predictions and strategies were not realised. Despite a greatly increased world population (see pages 23–24), there have been major increases in food production during the nineteenth century and especially in the second half of the twentieth century. At the same time, fertility rates have fallen, particularly as populations have become more urbanised.

In recent decades Malthus’s arguments have regained some favour. Neo-Malthusians have redeveloped some of his original ideas, in particular: there is ongoing evidence that population growth will eventually outstrip resources. In Sub-Saharan Africa, food production has fallen way behind population increases. The Malthusian checks of starvation and disease have been realised at various times since the 1960s — in Ethiopia, Somalia, Sudan, Chad and Niger, for example

Malthus’s viewpoints. Restricting the number of children a couple can have would help reduce the pressure on existing and future resource use, as well as food supplies. China’s one child policy can be seen as a Malthusian argument. While Neo-Malthusians support contraception and abortion as a means of population control, Malthus believed in self-control

Neo-Malthusians have extended the original argument to one concerning population growth, and an inevitable environmental degradation and resource overuse. They point to the apparent dwindling oil reserves of the world; the pressure on farming land, as well as its loss due to overuse and partial replacement with urban land uses; and the overfishing of the world’s oceans. Neo-Malthusians’ arguments were taken up in several influential publications including Ehrlich’s The Population Bomb (1968) and the Club of Rome’s The Limits to Growth (1972).