Population and development: Malthus versus Boserup

1. Population and development: Malthus versus Boserup BIAN2120/DEMO8024 Lecture 5 Robert Attenborough

2. Theories for situations of population stasis • I.e. of little or no population size change over long periods, slow growth at most • This may or may not mean equilibrium • Peter McDonald reviewed theories for this last time: homeostasis versus chaos • On a homeostasis model, feedback loops control any tendency to growth or decline • On chaos model, no such systematic control is at work: instead, extrinsic factors

3. Today, older theories for newer situations • Situations of dramatic population change • Also of radically changed patterns of society & economy in many regions • Development & modernization over the last 250 years or less • Somehow population has escaped homeostatic control, if there was any • Pop’n also interacts in complex ways with economic development: what causes what?

4. Is population growth good or bad for economic development? • Bad: Thomas Malthus • Good: Julian Simon – technological optimism: people are the ultimate resource • Neutral: Esther Boserup – greater density of population leads to technological change • These are not politically neutral ideas • Malthusian & neo-Malthusian can be terms of abuse; but what did Malthus say?

5. The Reverend Professor T.R. Malthus (1766-1834) • A mathematician, a clergyman, and Britain’s first professor of political economy • Also “father of demography” & its theory • One of the most influential thinkers of his day, which was a period of hectic social change: Industrial Revolution, Poor Laws • Provided one of the critical influences on Darwin’s thinking, hence on biology too

6. Malthus’s An Essay on the Principle of Population (1798) • First edition proposed a quite stark & simple model, & drew social policy conclusions from it • Perhaps for that reason, it had a dramatic impact on public debates • Nonetheless, it was quite a sketchy theory • Second and later versions were more nuanced in argument, much better supported evidentially - & less interesting

7. Malthus started from two postulata • 1. Food is necessary for survival • 2. “The passion between the sexes is necessary and will remain in its present condition” • From these he asserted that population growth would always have the potential to outpace economic growth • (Here’s the link to Darwin; though it’s a side-issue in the present context)

8. Thus some ‘check’ must limit population growth • Accordingly, Malthus saw two ways to keep population and resources in balance • 1: the ‘positive check’ – mortality; deaths • 2: the ‘preventive check’ – nuptiality; marriages, or rather constraints on them • He ruled out contraception as immoral

9. Positive check Population size rises Real income falls Mortality increases (poorer diets & living conditions) Population size falls Preventive check Population size rises Real income falls Marriages are postponed (they become unaffordable) Fertility falls Population size falls Positive and preventive checks

10. Malthus had very limited access to relevant data • Economic history (Phelps-Brown & Hopkins) & historical demography (Wrigley & Schofield) now allow a much fuller assessment of, say, the English historical data than Malthus himself could make • P-B & H produced real wages index based on wages of building workers & price of food • W & S inferred demography from parish registers

11. English results show … • a clear link between marriage & real wages • no clear link between mortality & real wages • Thus Malthus did appear to have captured an important facet of his own society • And the preventive check was predominant • However, Malthus wrote when England was entering the Industrial Revolution: the relation between economy & demography, including the links he stated, was changing radically

12. Thus Malthus was in a way successful • But his model took some aspects of society, economy, agriculture etc. as static • They were then undergoing rapid change, so his model described the past better than the future • The model does not handle change well • This is perhaps partly why he has subsequently been seen as conservative • ‘Malthusian’ sometimes even used to mean ‘opposed to social improvement’ – which would be a distortion even of TRM’s crudest version

13. Need to incorporate social change in population models • What is the rôle of population dynamics in situations of complex social, economic & technological change? • Such situations may be those of globalization in the present day • Or economic development, modernization • Or 19th-century industrialization • Or even earlier changes: agriculture & urbanization

14. Ester Boserup: first book 1965 • Danish agricultural economist, with field experience in India & other Asian countries • Interested in the interaction between population growth and innovation, e.g. in agricultural practice & technology • Although neither a demographer nor an anthropologist or archaeologist, she has proved to be an important influence on all

15. Archaeological background • How does past population growth relate to social, cultural, economic, technical change, e.g. agriculture, urbanization? • Archaeologists e.g. Childe had often taken the benefits of such changes to be obvious • Assumed they would be implemented as soon as society was advanced enough • Population growth would then follow

16. Boserup & archaeology • Boserup’s implication for archaeology was to turn previous assumption on its head • Population growth was not so much the end-product of social & technical change • Rather, population growth was an extrinsic pressure, driving changes which otherwise might not have happened • Far-reaching implications for archaeology & anthropology, still being explored

17. So what did Boserup actually say? • When a population is over-crowded, it evolves new forms of agriculture • High density of population is neutral, neither good nor bad, but usually needed for development of new techniques • With historical change, humankind has moved through a series of increasingly intensive agricultural systems • Each requires & supports more people

18. Stages of agricultural development • Gathering: always fallow • Forest fallow: 1-2 crops, 15-25 yrs fallow • Bush fallow: 4-6 crops, 8-10 yrs fallow • Short fallow: 1-2 crops, 1 yr fallow • Annual cropping: 1 crop, <1 yr fallow • Multi-cropping: 2+ crops, no fallow yrs • What triggers adoption of new methods? • New methods may require social change

19. Testing Boserup • No long-run data series like Wrigley & Schofield’s for Malthus is available for testing Boserup’s model • Nonetheless specific examples often support the propositions such as: farmers generally have to do more subsistence work than hunter-gatherers; work further increases with intensification of agriculture

20. Synthesis • Agricultural change is only part of a wider & more complex picture of development • When agricultural productivity comes from mechanization, as often nowadays, it is capital-intensive, not labour-intensive • Nonetheless Malthus & Boserup have both contributed stimulating models & insights • Lee (1986) & Wood (1998) have both put the two together into overall models of population dynamics, seeing them as complementary