1. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Theories of demographic and epidemiologic
transitions in the developing world
A brief literature review
Greg Matthews
University of Washington
Department of Sociology and
Center for Studies in Demography and Ecology
INDEPTH Network Mortality Workshop
21-25 June, 2010
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2. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Purpose
This presentation is motivated by the work beginning on the
INDEPTH project on transitions in the developing world.
The purpose of this talk is to set a baseline of knowledge about
demographic and epidemiologic transitions through a brief literature
review.
I will also suggest a tool for managing literature and citations, and
share an incomplete literature on the subject.
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3. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Background
• A demographic transition is a process by which a population
shifts from high levels of mortality and fertility to low levels of
mortality and fertility.
• Populations in Europe, North America, and parts of South
America and Asia have completed demographic transitions.
• Most of the developing world has begun demographic transitions.
• Developing-world populations appear to have more diverse levels
of mortality and fertility. They also appear to be taking different
routes along the way to low-fertility, low-mortality regimes.
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4. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Background
• Related to the demographic transition is the epidemiologic
transition.
• Epi transition theory poses that during the shift from high to low
mortality, the most prominent causes of death shift from causes
related to infectious disease to causes related to
non-communicable disease (NCD).
• This transition is also occuring in developing-world populations.
However, a resurgence in infectious disease, mainly HIV and
tuberculosis, has left some populations with a double-burden of
infectious and NCDs.
• For these reasons, the current epidemiologic and demographic
conditions in Africa and Asia appear unique in world history.
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5. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Background
These general observations quickly lead to many important questions
that will be studied here:
• How are mortality, fertility, and epidemiology changing in the
developing world?
• How are these changes different from those in historic transitions
and the propositions of transition theories?
• What are the implications of current trends for our transition
theories?
• What are the implications for societies?
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6. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Demographic transitions
• Beginning in the mid-20th century, demographers noted that
different populations had different rates of birth and death.
• They theorized that modernization and development led to
reduced mortality, and after a lag period, also reduced fertility.
• During the lag between mortality reduction and fertility
reduction, population grows quickly .
• This is famously the demographic transition theory.
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7. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Demographic transitions
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8. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Demographic transitions
• As more populations transitioned, and more data were analyzed,
it became clear that there is no single cause of all transitions
(Mason 1997).
• However, they are generally thought to be spurred by the social
and economic changes associated with the processes of:
• development/modernization,
• urbanization, and
• expanded education.
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9. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Mortality
Causes of historic mortality declines were:
• Improvements in the standard of living
• Changes in hygeine and sanitation (public health; personal
cleanliness)
• Improved medical knowledge and technology (vaccinations,
antibiotics, surgery...)
• Decreased virulence of some micro-organisms (Scarlet Fever)
The relative contributions of these causes depend on the historic
setting and timing of the mortality decline.
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10. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Epidemiological transitions
CONTRIBUTIONS OF CAUSES OF DEATH TO MORTALITY
DECLINE IN ENGLAND AND WALES, 1848-54 TO 1971
CAUSE OF DEATH % OF REDUCTION DUE TO CAUSE
I. Airborne Diseases 40.3 [32% before 1901]
Tuberculosis 17.5
Bronchitis/Pneumonia/Influenza 9.9
Scarlet Fever 6.2
II. Water- and Food-Borne Diseases 21.4 [46% before 1901]
Cholera, Diarrhea, Dysentery 10.8
Typhoid, Typhus 6.0
Tuberculosis (non-respiratory) 4.6
III. Other Disease Due to Micro-organisms 12.6 [35% before 1901]
Convulsions/Teething 8.0
Syphilis .3
Puerperal Fever .4
Other Infections 3.5
IV. Conditions Not Attributable to
Micro-Organisms 25.6 [10% before 1901]
Prematurity, Immaturity, Other Diseases 6.2
Old Age 8.7
Other Diseases of Digestive System 3.6
Violence 2.5
Source: Thomas McKeown, 1976. The Modern Rise of Population. New York: Academic
Press. Table 3.2, p. 55.
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11. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Decline in age-specific mortality rate
Source: Human Mortality Database. www.mortality.org
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12. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Decline in age-specific mortality rate, logged
Source: Human Mortality Database. www.mortality.org
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13. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Epidemiological transitions
Age groups that benefitted most in epi. transition were
• Infants (0-1) and
• Young children (1-4), and later
• Older adults.
because the most prominent causes of death for those groups were
controlled during the transition.
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14. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Fertility
Generally (though there are exceptions), fertility in the developed
world declined after a period of population growth that was a
consequence of mortality declines.
Hypothesized causal factors:
• Industrialization
• Expanded education
• Urbanization
• Reduced child and infant mortality
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15. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Fertility
Industrialization
• Changes in family economy
• Implications for women and children
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16. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Fertility
Expanded education
• First Generation Effects
• Reduced labor input for children
• Trade off quantity for quality
• Second Generation Effects
• Broadened world view
• Competition with parenthood
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17. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Fertility
Urbanization
• Increased cost of housing
• Rise of consumerism
• Reduced labor input from children
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18. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Fertility
Reduced infant and child mortality
• “Insurance” or “hoarding” behavior: In high-mortality settings,
having extra children is rational to ensure the desired family size
is met. This behavior might be stopped after a mortality decline.
• “Replacement” behavior: Fewer child deaths lead to fewer
replacement births and a smaller TFR.
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19. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Historic transitions
Summary
• Observations of historic transitions gave rise to Demographic
Transition Theory
• DTT has many challenges but general idea works in aggregate of
historic transitions
• Epidemiologic Transition Theory is also based on historic
transition: Deaths due to infectious disease are reduced and
deaths due to NCDs become more prominent as mortality falls
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20. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Mortality
• The developing world experienced tremendous reductions in
mortality over the 20th century.
• Like in the developed world, a mix of causes are responsible:
Improvements in standard of living, improved hygeine and
sanitation, and medical treatments.
• It appears that the contributions of each cause are quite different
in the developing world.
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21. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Life expectancy at birth
Source: United Nations, 2006
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22. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Infant mortality rate
Source: United Nations, 2006
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23. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Development and life expectancy at birth
Source: Preston, S.H. 1975. The changing relation of mortality and economic
development. Population Studies 29(2).
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24. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Mortality
• There were large gains in life expectancy in areas with low levels
of development.
• Factors other than income probably account for 75-90 percent of
gains in life expectancy; income growth accounts for only 10-25
percent.
• Improvements in mortality were related to exported technology,
so that countries could make progress even at levels of
development lower than developed countries had at the same
point in their mortality transition.
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25. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Mortality
Country Life expectancy GNI/capita % employed in
agriculture
Secondary
school enroll-
ment
Syria 73 $3,740 – 38
Iran 70 $8,050 23 71
Venezuela 73 $6,550 11 22
Tunisia 73 $7,900 – –
Malaysia 74 $10,340 19 –
U.S. 1976 73 $41,340 3.8 85-90
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26. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Fertility
• Fast population growth in developing world with mortality
declines.
• Birth rates in much of Asia and Latin America have fallen since
the 1970s.
• Sub-Saharan Africa had higher pre-transition birth rates that
have begun to fall recently but are still much higher than most of
the world.
• In Africa recently, there is debate over the possibility of a stall in
the fertility decline.
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27. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Crude birth rates
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28. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Comparing new and old fertility transitions
Differences between Europe and developing world in pre-transition
fertility
• Developing countries generally have higher rates of fertility than
pre-transition Europe.
• Differences in the institutional system of the family
• Differences in importance of particular intermediate variables (i.e.
marriage rates, age at marriage, breastfeeding practices,
contraceptive use, etc.)
• New international system brings pressure on households in
developing world (i.e. colonial history, family planning programs,
government aid programs)
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29. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Fertility
Criticisms of Demographic Transition Theory in the developing world
• Weak correlations between levels of urbanization or
industrialization and timing of beginning fertility decline
(Bongaarts and Watkins 1996).
• Several countries in Asia and Latin America began fertility
declines while agrarian and underdeveloped.
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30. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Fertility
Some variables to consider in developing-world fertility changes:
• Family patterns (age at marriage, nuclear or extended families)
• Socioeconomic development
• Education, especially for women
• Family planning
• Receptivity of culture
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31. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Fertility
Caldwell’s theory of wealth flows (1982)
• Family nucleation caused by economic or cultural forces.
• Children, not parents, become economic beneficiaries of family
life.
• Changes in relations of authority and obligation.
• In this way “wealth flows” from parents to children rather than
the other direction.
• Perhaps most applicable to sub-Saharan Africa.
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32. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Epidemiologic transitions
DISEASES RESPONSIBLE FOR LDC MORTALITY DECLINES,
1900-1970
CAUSE OF DEATH % OF REDUCTION DUE TO CAUSE
I. Airborne Diseases 45%
Bronchitis/Pneumonia/Influenza 30
Respiratory Tuberculosis 10
Smallpox 2
Measles 1
Diphtheria/Whooping Cough 2
II. Water-, Food-, and Fecesborne Diseases 9%
Diarrhea, Enteritis, Gastroenteritis 7
Typhoid 1
Cholera 1
III. Insectborne 15-35%
Malaria 13-33
Typhus 1
Plague 1
Source: Samuel H. Preston. 1980. “Causes and Consequences of Mortality Declines in
Less Developed Countries.” Pp. 289-360 in Richard A. Easterlin (ed.) Population and
Economic Change in Developing Countries. Chicago: University of Chicago Press.
Table 5.3
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33. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Epidemiologic transitions
• Success in management of many infectious diseases
• Reductions in insect-borne diseases, respiratory airborne diseases
• In some places, these advances have been reversed
• Increases in deaths due to NCDs
• With all these changes going on, layer on top of it all the HIV
epidemic and its many effects on mortality and fertility
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34. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
HIV
• HIV epidemics appear to have had a dramatic impact on
mortality and fertility in parts of the developing world, especially
in sub-Saharan Africa.
• In places suffering HIV epidemics, the epidemiological transition
toward NCDs is already occurring.
• The surge in communicable diseases (HIV, TB, etc.) add another
layer of morbidity and mortality on to the transition to NCDs.
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35. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
HIV and theory
DTT postulates that fertility declines as a result of declining child
mortality.
Example
Caldwell et. al. (1992) observed the first declines in African fertility
(in Botswana, Kenya and Zimbabwe) were in the only places with
levels of infant mortality lower than 70 per 1,000.
How will HIV epidemics affect fertility?
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36. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
HIV and fertility
• Increased child mortality could increase fertility:
• May lead to replacement or insurance fertility behavior.
• Reduces duration of breastfeeding, ending breastfeeding’s
contraceptive effect (perhaps not an important factor for parents
with HIV).
• Increased adult mortality could decrease fertility:
• May reduce prospective parents’ expectations of long-term
benefits of children.
• May reduce household income.
• Increased number of orphans require resources from relatives or
other caretakers.
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37. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
HIV and fertility
• Other factors related to HIV that could increase fertility:
• Efforts to reduce STD transmission may reduce pathological
sterility.
• Reduced breastfeeding (to prevent mother-to-child transmission)
could reduce inter-birth interval.
• Other factors related to HIV that could decrease fertility:
• Infected women may be less fertile due to illness, due to other
STDs, increased use of contraception, widowhood, and increased
resort to abortion.
• Use of condoms may increase as response to epidemic. (May also
have small positive effect on fertility if condoms replace more
effective methods of birth control.)
• Delayed age at marriage.
• Increased monogamy.
• Increased celibacy.
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38. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Transitions in the developing world
Summary
• Mortality transitions encouraged by imported technology, control
of infectious disease
• Beginnings of epi transition observed in higher rates of NCDs
• For some populations, resurgence of infectious diseases plus HIV
epidemic have reversed previous gains in life expectancy
• HIV epidemics have a very complex and multifaceted impact on
mortality and fertility processes
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39. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for theory
The transition theories outlined above are mainly based on historical
transitions. Their utility in explaining current transitions can be
questioned.
• Are developing-world transitions, especially in the era of
HIV/AIDS, fundamentally different from historical transitions
that they need a new theory?
• Or can classic theories accomodate modern transitions by
adjusting their claims?
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40. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for theory
Social science relies on theory to make sense of empirical observations
and to relate similar processes across regions of the world.
If the foundational models of transitions can not be applied to parts of
Africa and Asia, population scientists will struggle to explain current
observations and to postulate population dynamics in the future.
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41. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for theory
More specifically...
Transitions in these sites need to be documented to first of all test the
hypotheses of transition theories.
• How do changes in mortality affect changes in fertility?
• How does the cause-of-death profile change as mortality declines?
• How is HIV/AIDS affecting these trends?
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42. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for society
Many aspects of society are impacted by demographic and
epidemiologic transitions. Here are five areas that this work may focus
on.
• Age composition
• Gender
• Fertility decisions
• Family structure
• Health services
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43. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for society
Age composition
• HIV mortality and morbidity remove working-age adults from the
population (anti-retroviral treatments may add productive years
of life)
• Reductions in infectious disease increase survival for young
children
• NCD mortality and morbidity affect adults and older adults
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44. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for society
Gender
• How do transitions impact gender relations?
• Women’s employment and education
• Family and household relationships
• HIV impacts sex ratio: sex ratio weighted toward males at young
adult ages, toward females at older ages.
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45. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for society
Fertility decisions
• How does increasing child and adult mortality affect fertility
decision-making?
• Children who have HIV are infected by maternal transmission.
Mothers with HIV have fewer children because of illness. This
reduces the likelihood of replacement behavior.
• Possibility of insurance behavior in the community, as others
families see children dying.
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46. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for society
Family structure
• HIV leads to more single orphans and some double orphans.
• Extended families become caretakers.
• Rise in NCDs requires caretaking of older family members
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47. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Implications for society
Health services
• In sub-Saharan Africa, services mainly developed to treat
infectious diseases.
• Problems meeting needs of patients requiring chronic care.
• Treatment of HIV (ARTs) and NCDs require long-term chronic
care .
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48. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Literature
• Saved folder of PDFs of journal articles
• Can share that literature here
• Also able to share online
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49. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Citation management
• Mendeley: www.mendeley.com
• Free
• Save articles as attachments to bibliographic records
• Create libraries and export citations
• Social networking feature
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50. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Mendeley
Demonstration
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51. Background Historic transitions Developing-world transitions Theory Society Literature and citations
Contact
Greg Matthews:
gmm06@uw.edu
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