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Demographic impact of introducing modern medicine to a subsistence-level agrarian population: A simulation


Typical of many peasant communities in the Third World, the highland Indian population of Nuñoa, Peru operates close to its capacity for providing members with adequate nutrition. High birth and mortality rates maintain population stability in groups such as this. The introduction of modern medical services could decrease mortality and stimulate population growth, thus upsetting stability of the population size.

Development of Third World countries includes improving health of subsistence-level populations by providing modern medical services. However, such changes would have secondary effects which should be anticipated. Using the Nuñoa population as a representative data base, and making a number of simplifying assumptions to increase the generality of this case, a simulation model has been devised to explore some of the consequences of introducing modern medical services.

The model predicts that decreased mortality would initiate population growth. Some growth would be supported by changes in individual consumption patterns. But unless decreases in birth rate stabilized the population, it would increase beyond the level sustainable by local resources. Starvation or emigration would cause the population to crash. The model identifies several strategies for reducing birth rate sufficiently to avoid a population crash. Despite these strategies, increased equilibrium size of population would reduce per capita consumption. Since the population lives at the subsistence level, hardship, hunger, and even starvation could result. Thus, introduction of modern medical services could involve a trade-off between short-term improvements in health and. long-term economic hardship for the population. The model suggests that improved well-being of the population would require not only modern medical services but also (a) reduced birth rates; and (b) the improved technology necessary to increase food production.

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Blankenship, J.C., Thomas, R.B. Demographic impact of introducing modern medicine to a subsistence-level agrarian population: A simulation. Environmental Management 1, 401–417 (1977). https://doi.org/10.1007/BF01866997

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Key words

  • Demographic prediction
  • Developing populations
  • Ecosystem models
  • Population explosion
  • Public health