Causes and consequences of mortality decline in the less developed countries by Samuel H. Preston. This article is presented in the context of Bangladesh. The sole purpose of this paper is to identify the factors responsible for the dramatic decline of mortality rates in the less developed countries of Asia, Africa and Latin America. These factors were broadly termed as 'social and economic development' and 'technical changes'.

1. This is your
presentation title

2. Nishat Zareen
Roll No: FM-044-029
3rd year, 6th Semester
Course no:305
Course Name: Population Theories
Department of Population Sciences
University of Dhaka

3. ▣This paper distinguishes the elements behind mortality
decline in lesser developed nations of Asia, Africa and
Latin America and gives estimates that how critical the
effects of these factors are in demographic and economic
processes.
▣These factors are namely:
1. Social and economic development with improved
nutrition, housing, clothing, water supply and medical
care.
2. The great increase in government and social aid.
3. The reduction in health care cost by technological
improvements.

4. ▣After analyzing the data from many less developed
nations of 3 continents, Preston saw that fertility rates
have remained quite same between the period of 1850
to 1970 (40/1000 to 41/1000), but mortality rates have
declined a great deal (38/1000 to 17/1000).
▣The sole purpose of this paper is,
I. To identify the factors responsible for the mortality
improvements in less developed countries and
provide estimates of their relative importance.
II. To begin tracing the effect of these improvements
on demographic and economic processes.

5. 1.
Transition headlineLet’s start with the first set of slides
Causes of declining
mortality

6. Causes of mortality decline can be broadly
differentiated from 2 point of views
1. Social and Economic
Development:
-private standards of
nutrition
-housing
-clothing
-transportation
-medical care
2. Technical changes:
-immunization against
a host of infectious
diseases
-vector eradication
-chemotherapy

7. ▣During 1980s the rate of death was higher among
children under 5 years and women In Bangladesh. Major
causes of death were infectious and contagious diseases
such as cholera dysentery, respiratory diseases or so.
▣Mortality rates started to fall due to countrywide
introduction of immunization programs for preventable
diseases. It started in 1979, but the coverage was below
2% until 1985. The intensified immunization program
was expanded in phases. It covered 8 thana in 1985(first
phase); 190 thana in 1988(second phase) and whole
country by the end of 1989 (Talukdar et al. 1991).
▣Improved standard of living, female education,
improved nutritional status aided a great deal to reduce
mortality rates between two of the most vulnerable
groups, women and children.

8. Effect of private income levels on mortality:
▣Mortality rates are directly influenced by private living
standards and national level of economic development.
Richer countries not only have richer people but also have
richer programs. And Preston also tried to prove that a
nation’s life expectancy is a byproduct of its national
income.
▣In Bangladesh too income level has direct influence on
mortality status. Khan (1986) found that, the death rate
among <5 children is lower in families who can afford 3
meals per day and their nutrition intake is richer and these
children are less prone to stunting.

9. Causes of death responsible for mortality declines

10. ▣Among other major causes of mortality was Malaria. Rates
of Malaria have declined largely after anti malaria
campaigns run by the government of many less developed
countries like Sri Lanka, Guatemala during 1960-1970.

11. ▣In the early years communicable diseases
were the major health hazards. Diarrheal
disease, malnutrition and pneumonia were the
most prevalent cause of death during the 1980s
(Bangladesh Disease and Disease Control-
country studies).
▣These trends have changed over time. Non
communicable diseases such as cardiovascular
diseases (40%), diabetes, cerebrovascular
diseases, hepatic diseases cancer are the major
causes of death among the population of
Bangladesh (mortality profile Bangladesh
2011).

12. Influences operating on the causes of death
▣Major influences operating the causes of
death are
I. Nutritional Intake
II. Standard of living
III. Availability of vector control and
immunization programs
IV. Condition of water supply and sewage
disposal.

13. The role of MDC’s in LDC gains:
▣MDCs have played a decisive role in the mortality
declines experienced by LDCs. Sulfa drugs, antibiotics, and
most vaccines and insecticides, including DDT, have been
developed in laboratories within MDCs. MDCs contributed
5,764 technical assistance workers in health services to
LDCs in 1968.
▣International aid for health purposes is a small part of
total health expenditures in LDCs. MDC contributions to
mortality declines in LDCs have not been primarily
financial. They seem to have consisted of the development
of low-cost health measures exploitable on a massive

14. scale, demonstration of their effectiveness in relatively
small areas, training and provision of personnel, and
occasionally the initiation of large-scale Programs whose
major cost was often absorbed By the MDCs.
▣The financial contributions are associated with an
increase in life expectancy of about one year in the
17 LDCs between 1940 and 1970.
In the year 2017, Bangladesh received USD 570 million
from world bank to improve health sector and public
procurement performance. Many other foreign agencies
such as Red Cross, Oxfam , USAid helps Bangladesh in
many ways to improve their health sector.

15. Consequences of mortality reductions
▣Mortality decline increases the rate of population
growth.
▣Increases the rate of natural increase by the decline
average death rates between age zero and mean age at
child bearing.
▣Mortality change affects the age distribution of a
population.
▣Survivorship increases.
▣Declining mortality rates increases the population of
age group <10 and 75> years.
▣Brings a change in the overall population
composition.

16. Economic and behavioral responses
▣To aggregate economic and behavioral responses to mortality decline,
it is useful to recognize that all of the responses must make themselves
felt through one of four indexes.
▣This is the basic Malthusian model, in which the "passion between the
sexes“ placed a floor on the crude birthrate, a subsistence level of
production bounded Rpc from below, migration was defined as
impossible, and slow Technical change and rapidly diminishing returns
to labor constrained Rp from above.

17. Declines in Crude Birthrates
▣There are multiple ways through which mortality can
induce changes in fertility. 3 of the effects are quasi-
biological.
-1st quasi-biological effect is that declines in mortality
change the age structure in such a way as to reduce the
proportion of the population in the childbearing years and
to reduce crude birthrates if age-specific fertility rates
remain constant.
▣ -A second biological mechanism operates through breast-
feeding. Breast-feeding inhibits ovulation, particularly in
poorly nourished populations. Survival of the previous
birth, by extending lactation, tends to delay the arrival of
the next birth. Estimates of the average amount of net delay
range as high as 12-13 months in Senegal, Bangladesh.

18. ▣A 3rd quasi-biological effect is that, mortality declines make
it more likely that marriages will survive through the end of
their partner’s reproductive periods.

19. Declines in Crude Rate of Net
Migration
▣When subnational territories are considered, the
migration response probably becomes more
consequential, because the export of population growth
from one area to another faces fewer legal, cultural, and
institutional .impediments.
▣It is often suggested that a large proportion of rural
natural increase simply cannot be exported to urban
areas simply because the cities cannot create enough
new jobs.

20. Increases in Growth Rates of Total
Production.
▣A decline in crude death rate generally
increases the size of the labor force growth
rate.
▣Lower mortality population can look forward
to longer lives in which to reap the benefits of
personal investment.
▣The present value of investments with a long
gestation period such as extended schooling,
retirement equities or children necessarily rises
when mortality rates fall.

21. Over the years the mortality trend of Bangladesh has
changed a great deal. CDR has declined 6 points since 1981
to 2014 (5.64). Maternal mortality rate in Bangladesh is 170
per 1000000 population which used to be 574 per 1000000
population just about 20 years ago or so. Infant mortality
rate of Bangladesh fell gradually from 154.23 deaths per
thousand live births in 1966 to 29.5 deaths per thousand live
births in 2015.
Such dramatic shifts in mortality rates have been possible
due to improvement in life standards, awareness build up,
education, rich nutritional intake, well arranged sanitation
system, availability of safe drinking waters, immunization
programs etc.

22. The pathway through which this success was
achieved were social and economic
development, technological improvements,
government and social aid just like Preston
predicted. Like other less developed countries,
Bangladesh also followed a similar trend in
mortality decline.

23. thanks!
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