tribhuvan university padma kanya multiple campus population studies masters in arts demographuc models

1. Demographic Models
Presented By: Roji Maharjan
MA 2nd semester
Population Studies
Padma Kanya Multiple Campus

2. Objectives:
• To explain Demographic Model
• To discuss different Demographic Model Life Tables
• To point out the uses of Demographic Models in Demographic
Analysis

3. Demographic Models:
• Demographic models are an attempt to represent demographic
processes in the form of a mathematical function or set of
functions relating two or more measurable demographic
variables.
• It attempt to present reality, they are based to greater or lesser
extent to actual data.
• It refers to all mathematical statistical models that are applied to
study demographic phenomena.
• They are widely used to improve data quality, to compare
demographic outcomes and process across population.
• They are used to construct the specific life tables in the situations
of unavailability of adequate data.

4. Types of Demographic Model Life tables:
1. United Nations Model Life Tables
2. Coale-Demeny Model Life Tables
3. Ledermann’s Model Life Tables
4. Brass-Logit Model Life Tables
5. United Nations Life Tables for Developing Countries

5. 1. United Nations Model Life Tables:
• The first set of model life tables constructed using 158 life tables
for each sex.
• They were constructed by assuming that the value of each 5𝑞𝑥 , a
quadratic function of the previous q value, namely 5𝑞𝑥−5 (except
for first two age group 𝑞0 and 4𝑞1, all other groups considered
are 5 years in length.)
• It covers the range of life expectancy at birth from 20 to 73.9
years in the interval of 5 years up to age 55.

6. 2. Coale-Demeny Life table:
• It was published in 1966 and derived from a set of 192 life tables
by sex recorded for actual populations and derived from
registered data.
• These were constructed by fitting linear regression equation
linking 𝑛𝑞𝑥 and 𝑒10
0
.
• Life expectancy ranging from 20 –77.5 years.
• There are four different sets of mortality pattern. They are:
• East model: characterized by high child mortality in relation to
infant mortality. It consists of 31 life tables and life expectancy
ranges from 36.3 to 72.3 years. The mortality pattern is `U’
shaped curve.

7. • North Model: characterized by comparatively low infant
mortality, high child mortality and low old age mortality beyond
age 50. It consists of 9 life tables and life expectancy range from
44.4 to 74.7 years. The mortality pattern is ‘n’ shaped curve.
• South Model: characterized by a) high child mortality in relation
to infant mortality at high over all mortality b) low infant and
child mortality at low over all mortality. It consists of 22 life
tables and life expectancy ranges from 35.7 to 68.8 years.
mortality pattern is ‘V’ shaped curve.
• West Model: Characterized by most general mortality pattern. It
consists of 130 life tables and life expectancy range from 38.6 to
75.2 years.

8. 3. Ledermann’s Model Life Tables:
• This were developed in 1969 based on factors analysis of 154
empirical tables.
• This life table considers five factors. They are general mortality
pattern, relation between child and adult mortality, pattern of
mortality at older ages, pattern of mortality below age 5 years and
differential between male and female mortality in the age range
from 5 to 70 years.
• This model life tables developed based on regression analysis.

9. 4. Brass- Logit Model Life Tables:
• It is based on the assumption that two distinct age patterns of
mortality can be related to each other by a linear transformation
of the logit of their respective survivorship probabilities.
• It provides greater degree of flexibility.
• The main argument is that the transformation of the probability of
survival lx makes the relationship between corresponding
probabilities for different life tables may be approximately linear.

10. 5. UN Model Life Tables For Developing
Countries
• This model life table published on the basis of data from
developing countries in 1982.
• It consists of 36 life tables by sex.
• It covers wide range of mortality levels geographically.
• This model developed based on 5 distinct patterns of mortality.
• They are as fallows:

11. 1. Latin American Pattern: High mortality during infant and
childhood year due to excess of diarrheal and parasitic disease.
2. Chilean Pattern: Extremely high infant and child mortality rate
appears from respiratory disease and related to early weaning.
3. South Asian Pattern: High mortality under age 15 and over 55
because of Diarrheal and parasitic disease and respiratory
disease.
4. The Far Eastern Pattern: Very high death rates at older ages
compared with those a younger ages due to past history of
Tuberculosis.
5. General Pattern: Average four regional pattern which are
similar to west family of C-D set.

12. Uses of Demographic Models in
Demographic Analysis:
• It helps in understanding levels and patterns of mortality with
very little demographic data.
• It helps to construct a system that gives schedules of mortality
by sex and age.
• Demographic tool for populations lacking accurate
demographic data.
• It gives the accuracy in the estimations.
• Life tables for both sexes.
• It helps to improve the data quality.
• It helps to compare demographic outcomes.

13. Thank you!!