Malthus theory of population growth.

1. MALTHUS THEORY OF
POPULATION GROWTH
ISTIAQE AHMED TANIM
ROLL: 117646
DEPERTMENT OF GEOGRAPHY & ENVIRONMENT
JAGANNATH UNIVERSITY, DHAKA

2. Thomas Malthus
o Born: February 14, 1766, Surrey, United Kingdom.
o Died: December 29, 1834, Bath, United Kingdom.
o Wrote ‘An essay in the First Principle of
population’ first published in 1798
o Debatable whether the principles of Malthus two
hundred years ago ( that were very revolutionary
and controversial ) have any relevance to the
modern world.
o The world population in 1798 was at nine million
people. We have now passed the seven billion
mark.

3. The Core Principles of Malthus
• Food is necessary for human existence.
• Human population tends to grow faster than the power in the
earth to produce subsistence.
• The effects of these two unequal powers must be kept equal.
• Since humans tend not to limit their population size voluntarily -
“preventive checks” in Malthus’ terminology.

4. Theory of Population
• Malthus very concerned by the condition of the poor and
particularly by rural poverty.
• Because of this he was skeptical of notions of the perfectibility of
society.
• 1st Edition of the Essay is an a priori polemic—the 2nd Edition
included much empirical observation.
• Inspired Darwin’s idea of “the struggle for survival” .

5. Malthus Theory
• In 1798 Thomas Malthus published his views on the effect of
population on food supply. His theory has two basic principles:
• Population grows at a geometric rate i.e. 1, 2, 4, 16, 32, etc.
• Food production increases at an arithmetic rate i.e. 1, 2, 3, 4, etc.

6. Geometric And Arithmetic Ratios
• Population, when unchecked, grows in a geometric ratio.
• Population, if unchecked, will double every 25 years [ a geometric
progression is 1, 2, 4, 8, 16, 32, 64, etc.].
• Evidence from the US where land is abundant.
• Subsistence grows at an arithmetic ratio [1, 2, 3, 4, 5, 6 etc.].
• Subsistence still grows, but due to the different growth ratios
population must eventually press against the means of subsistence.

7. Malthus Theory

8. Malthus (cont.)

9. Proposed Solutions of Malthus
• Malthus suggested that once this ceiling (catastrophe)
had been reached, further growth in population would
be prevented by negative and positive checks. He saw
the checks as a natural method of population.

10. Negative Checks (Decreased Birth Rate)
• Negative Checks were used to limit the population growth. It
included abstinence/ postponement of marriage which lowered
the fertility rate.
• Malthus favored moral restraint (including late marriage and
sexual abstinence) as a check on population growth. However, it is
worth noting that Malthus proposed this only for the working and
poor classes!

11. Positive Checks (Increased Death Rate)
• Positive Checks were ways to reduce population size by
events such as famine, disease, war - increasing the
mortality rate and reducing life expectancy.

12. Malthusian Catastrophe
• A Malthusian catastrophe (also phrased Malthusian check, Malthusian crisis,
Malthusian disaster, or Malthusian nightmare) was originally foreseen to be a
forced return to subsistence-level conditions once population growth had
outpaced agricultural production. Later formulations consider economic
growth limits as well.
• Malthusian catastrophe are very similar to the Iron Law of Wages.
• The main difference is that the Malthusian theories predict what will happen
over several generations or centuries, whereas the Iron Law of Wages predicts
what will happen in a matter of years and decades.

13. Criticism
• As a general rule the following points were raised as criticism against
Malthusian Theory
• The ratio of arithmetical progression of means of subsistence and the geometrical progression of
population growth was never proved.
• In so many cases the theory of the growth of the means of subsistence in arithmetical ratio was
not proved.
• Malthus did not clearly distinguish between fecundity and fertility.
• Malthus did not succeed in connecting positive and preventive checks with his theory.
• Friedrich Engels also criticizes the Malthusian catastrophe because Malthus failed to see that
surplus population is connected to surplus wealth, surplus capital, and surplus landed property.
• Ester Boserup wrote that population levels determine agricultural methods, rather than
agricultural methods determining population (via food supply).

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