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UGC NET

DAILY
CLASS NOTES
Economics

Environmental Economics and Demography

Lecture – 5
Health, Morbidity, DALY, HALE, PYLL, QALY;
Migration
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Health, Morbidity, DALY, HALE, PYLL, QALY; Migration

Health
• 22nd July 1946 [w.e.f. 7th April 1948] Constitution of the World Health Organisation, health
has been defined as ‘a state of complete physical, mental and social wellbeing and not
merely the absence of disease or infirmity.
• The enjoyment of highest attainable standard of health is the fundamental rights of every
human being without distinction of race, religion, political belief and economic or social
condition.
• In economics, health is not only a state of physical and mental well being with absence of
diseases but also as a COMMODITY- a durable or capital stock which makes a person
efficient and productive.
• Over time, the stock of health depreciates with age, which may be upkept with due
investments in medical and recreational ventures. Death happens when individual’s stock
of health < below the critical minimum level.
• Thus, people desire good health as a commodity both for consumption and investment
purposes. Good health is a durable consumption good because it yields utility by improving
the quality of life.

Morbidity Indicators [Morbidity means illness and is measured in two ways:]

Prevalence Rate
• It is a measure to determine the level of morbidity like to determine the likelihood of
people getting a disease. A PR is the total number of cases of a disease existing in a
population divided by the total population in a particular area. Eg- If in Delhi, say 1500
fresh cases of COVID 19 positive have been tested and already 3500 people are infected
due to COIVD 19, then PR of COVID is [3500+1500]/ total population of Delhi.
Incidence Rate:
● It is a measure of disease that allows us to determine a person’s probability of being
diagnosed with a disease during a given period of time. Therefore, it is the number of newly
diagnosed cases of a disease.
• An incidence rate is the number of new cases of a disease divided by the number of persons
at risk for the disease. For instance, if over the course of one month, 50,000 new people
out 2 lakh sample are found to be infected from COVID 19, who were not infected at the
beginning of the period, then the incidence of COVID 19 is 50000/2,00,000.
• Health Status Indicator: These are the measurement of health status of a given conveyed
by using various indices including mortality and morbidity. For ex- Low Birth Weight
(LBW) is an indicator defined as less than 2,500 gm of a newly born child (weighed during
the first hour of life).
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Burden of Disease Indicators

At individual level, BoD refers to the overall impact of diseases and injuries. At societal level,
it refers to the economic costs of diseases.
Global Burden of Disease (GBD) is an indicator published by WB in its WDR. It measures the
total loss of health resulting from diseases and injuries. The GBD concept, first published in 1996,
constituted the most comprehensive and consistent set of estimates of mortality and morbidity yet
produced (Murray & Lopez, 1996), and WHO now regularly develops GBD estimates at regional
and global level for a set of more than 135 causes of disease and injury (Mathers et al., 2002;
WHO, 2002a).
A GBD study aims to quantify the burden of premature mortality and disability for major
diseases or disease groups, and uses a summary measure of population health, the DALY,
to combine estimates of the years of life lost and years lived with disabilities. The data are
also broken down by age, sex and region
Disease burden is thus the impact of a health problem as measured by financial cost, mortality,
morbidity, etc.
It is often expressed in terms of quality adjusted life years (QALYs) or disability-adjusted life
years (DALYs), both of which quantifies the number of years lost due to disease (YLDs).
Summary measures of population health measure the health of a population by combining data
on mortality and non-fatal health outcomes into a single number. Besides the DALY,
several other such measures have been devised, including the Quality-Adjusted Life Year
(QALY), the Disability-Adjusted Life Expectancy (DALE) and the Healthy Life Year
(HeaLY) (Weinstein & Stason, 1977; Murray & Lopez, 1996; Hyder, Rotllant & Morrow,
1998; Murray, Salomon & Mathers, 2000). The benefits and challenges of these measures
have been examined (Anand & Hanson, 1997; Williams, 1999; Murray & Lopez, 1999b,
Murray, Salomon & Mathers, 2000; Murray et al., 2002).
As the DALY has been the most widely-used measure. The DALY measures health gaps as
opposed to health expectancies. It measures the difference between a current situation and
an ideal situation where everyone lives up to the age of the standard life expectancy, and
in perfect health. Based on life tables, the standard life expectancy at birth is set at 80 years
for men and 82.5 for women.
The DALY combines in one measure the time lived with disability and the time lost due to
premature mortality: DALY = YLL + YLD

• DALY = YLL + YLD

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• The YLL metric essentially corresponds to the number of deaths multiplied by the standard
life expectancy at the age at which death occurs, and it can be rated according to social
preferences. The basic formula for calculating the YLL for a given cause, age or sex, is:
YLL = N x L

• To estimate YLD on a population basis, the number of disability cases is multiplied by the
average duration of the disease and a weight factor that reflects the severity of the disease
on a scale from 0 (perfect health) to 1 (dead). The basic formula (without applying social
preferences) for one disabling event is: YLD = I x DW x L

HALE is a measure of population health that takes into account mortality and morbidity.
It adjusts overall life expectancy by the amount of time lived in less than perfect health.
This is calculated by subtracting from the life expectancy a figure which is the number of
years lived with disability multiplied by a weighting to represent the effect of the disability.
If:
A = years lived healthily
B = years lived with disability
A+B = life expectancy
A+fB = healthy life expectancy, where f is a weighting to reflect disability level.

Quality Adjusted Life Year (QALY):

● It was invented in the 1970s and has become an internationally recognised indicator since
the mid-1990s. QALY is the arithmetic product of life expectancy combined with a
measure of the quality of life-years remaining. That is, it is the time a person is likely to
spend in a particular state of health, weighted by a utility score from standard valuations.
• QALY of ‘1’ indicates perfect health and ‘0’ equates to death. Certain health states are like
severe disability and pain, they are regarded as worse than death and are even assigned
negative values.
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Disability-Adjusted Life Year (DALY):

• It is an alternative tool (emerged in the early 1990s) as a means of quantifying the burden
of disease. It sums up years of life lost (YLL) due to premature mortality and years lived
in disability / disease (YLD).
• YLL is calculated as the number of deaths at each age multiplied by the standard life
expectancy for each age.
• YLD represents the number of disease/disability cases in a period multiplied by the average
duration of disease/disability weighted by a disease/ disability factor.
• Conversely, DALYs measure the amount of life lost in a population as a result of premature
death or disability. They can be used to estimate the burden of disease on populations.
DALYs were used in the Global Burden of Disease study to enable mortality and morbidity
comparisons to be made across countries. Weightings were applied to conditions by using
the time trade off approach, in which people were asked to consider living more years in
imperfect health compared with fewer years in perfect health. The study also placed more
weight on the life of a young adult compared with a newborn.
• For instance, a woman with a standard life expectancy of 82.5 years, dying at age 50, would
suffer 32.5 YLL. If she additionally turned blind at aged 45, this would add 5 years spent
in a disability state. If the weight factor is 0.33, then it results in 0.33 x 5 = 1.65 YLD. In
total, this would amount to 32.50 + 1.65 = 34.15 DALYs.
• For DALYs, the scale used to measure the health state is inverted to a ‘severity scale’,
where ‘0’ equates perfect health and ‘1’ equates death

Potential Years of Life Lost (PYLL)

• A measure related to HALE and DALY, this measure attempts to quantify the potential
years of life lost by looking at average age of death from conditions compared to average
life expectancy. PYLL can be expressed absolutely or as a rate relative to the population
at risk.
• The calculation for Potential Years of Life Lost (PYLL) involves adding up deaths due to
a particular cause or multiple causes, at each age and multiplying this with the number of
remaining years to live up to a selected age limit. The limit of 70 years is frequently chosen
(sometimes 65 is chosen).

Sullivan’s index’ ‘Disability Free Life Expectancy’ “Active Life Expectancy”

‘Life expectancy’ MINUS ‘duration of disability’. Health expectancy calculated by Sullivan’s
method is the number of remaining years, at a particular age, that an individual can expect to live
in a healthy state.
• The data for calculation is obtained from
▪ population surveys and
▪ life tables

• The age-specific prevalence is directly applied to person-year of the life table: it provides
▪ The total number of years spent with disability,
▪ The total number of years lived without disability
▪ DFLE/ Active LE/ Sullivan's index is more relevant for elderly population
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Disability indicators (Summary)

HALE (Health – Adjusted Life Expectancy) 1. HALE (Health–Adjusted Life Expectancy)
• Previously known as DALE (disability adjusted life 2. QALY (Quality-adjusted life years)
expectancy) 3. Disability – free life expectancy (active life
• Indicator used to measure healthy life expectancy expectancy)
• Based on life expectancy at birth BUT includes an 4. Disability-adjusted life years (DALY)
adjustment for time spent in poor health
• Definition: equivalent number of years in full
health that a new-born can expect to live based on QALY (Quality – Adjusted Life Years)
current rates of ill health and mortality • A measure of disease burden including both:
1) Quality and 2) Quantity of life lived
Used in assessing the value for money of a
medical intervention
DFLE: Disability – free life expectancy Based on the number or years of life that would
be added by intervention’
Active life expectancy Each year in perfect health = 1.0 | Death = 0.0
Average number of years an individual 1 QALY = one year of life X one utility value = one
is expected to live free of disability if year of life lived in perfect health
current pattern of mortality and disability Half a year lived in perfect health is equivalent to
continue to apply 0.5 QALY = 1 year X 0.5 utility value

Migration
Population growth is determined by fertility, mortality, and migration. Population growth may
be expressed as:
● Natural growth = Birth rate – Death rate
● Actual Growth = Birth rate – Death rate + Immigration – Emigration
● It should be noted that while migration is to move from one place to another as temporary
measure, immigration and emigration lead to permanent change in the status of resident.
Secondly, migration can be within the country or internationally, but emigration and
immigration are only internationally with permanency.

Migration is the movement of people which involves a change in the place of normal residence
of people from one settlement to another. It occurs due to push and pull factors.

✔ Push factors are those that compel humans to leave a place of origin, for instance, war,
political unrest, poverty, natural calamity, lack of opportunity, etc.

✔ Pull factors are those that attract humans towards a particular place. whereas some of the
major pull factors, for instance, better & more opportunity, glamour, fertile land and soil,
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good means of transport and communication, high levels of urbanization, industrialization,

etc.

When people migrate within the same country it is called internal migration. When migration
involves crossing the boundaries of a given country, it is called international migration. Migration
results in multi-dimensional changes in the population composition - ethnic, ethnolingual,
religious, demographic, cultural and economic. The structural contexts of migrants itself has
bearing in migration and what it means to be a migrant.
Types of Migration
• Cyclic or Circulatory Migration: Movements of individuals that involve only a
temporary change of residence are generally not considered as migration. This type of
movement is known as nomadism or pastoral nomadism. If this movement of the people is
along with their animal stock – sheep, goats and cattle between two fixed points it is called
transhumance. The movement of farm workers is also a kind of cyclical migration because
they follow the growing season. Tourism and commutation are not generally considered as
migration. Some migrations are cyclic in nature, which means that they are like
oscillations/ circuits. People migrate between two fixed points. It is an annual cycle, to be
completed within the same year.

• Internal and External (International) Migration: When people migrate within the
country of their birth/residence/domicile, it is called internal migration. The word internal
here means movement within the bounds of the home country. When people move from
one country to another, it is called international migration. Such migrations involve
crossing the borders of the countries. Sometimes the driving force is a push factor.

• Primitive or Early Migration: Distinction has often been made between Early/Primitive
migration and forced/ impelled migration.

⮚ Early migration, popularly during the prehistoric and early historic times were of
random nature and mainly were not planned migration. People used to migrate from
one place to another in search of food, shelter and water.

⮚ Forced or Impelled Migration: When individuals or groups decide to leave their

home country in order to avoid devastation caused by drought, famine, epidemics,
war, civil strife, or terrorising dictatorial regimes, it is called forced migration. Like
migration after independence 1947. Refugee Movements: Example: Bihari
Muslims who migrated to East Pakistan immediately after the partition of British
India in 1947 are still living in camps, even though fifty-seven years have passed.
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● Seasonal and Periodic Migration: Migrations are sometimes seasonal or periodic.

Common among the nomadic people living on the margins of the deserts. Periodic
Migration: Trewartha refers to periodic movements, which are related to vacations, fun
making or business. For e.g. travels are related to pilgrimage to sacred places, large fairs,
such as Kumbh Mela and Pushkar Mela. Millions of people in India go on pilgrimage for
a holy dip in the rivers and lakes to perform religious rites.
● Another type of periodic migration is the movement of an individual from his original
place of residence for a period of few years. He visits his home periodically. The main
aim of this type of migration is to earn more and to send remittances to the family in the
native place to establish themselves after they return to their original homes. However,
initially their intentions were to remain there only temporarily’

Types of Migration
Rao (1986) has divided the pattern of migration into three categories on the basis of causal factors:
• (1) Involuntary migration: migration under crisis such as war, transfer of population,
riots, floods, droughts, earthquakes, construction of the hydel projects. It also includes
marriage migration, virilocal, uxolocal or neolocal and transfer migration.

• (2) Voluntary migration: means people move out in search of livelihood. It includes
nomads, shifting cultivators, traders and salesman, artisans and labourers.

• (3) Transhumance migration: it is a special type of migration between two sets of

settlements in different seasons.

Migration Streams
While dealing with internal migration demographers and population scientists generally recognise
four streams. The criterion is the direction of movement of population from the places of origin
to the places of destination. The migration within the bounds of the same country generates four
main streams as given below:
1. rural-rural migration stream; In villages where the economy is based on agriculture,
people migrate from one village to another either for harvesting or sowing the crops or
both. The assumption is that the native village is overcrowded and agriculturally less
productive as compared to the village of destination. In this form of migration, the migrants
are mostly males. Sometimes, women also migrate along with the male members of the
family. In countries like India, young women are married to a person living at a certain
distance from their parental village. The reason is that the marriages cannot be contracted
within a radius of 4-5 miles (6-8 kms.) This no-marriage field is treated as the taboo zone.
However, this practice is a feature of North India only. There is no such practice in the
south, where the girls are generally married to their paternal or maternal cousins.\
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2. rural-urban migration stream; In the less developed countries, like India, Nepal and
Bangladesh, rural to urban migration is a common phenomenon. In regions where the rural
population densities are very high and the pace of urban-industrial development is fast,
rural-urban stream is most common. These towns/cities attract the ‘surplus labour’ from
nearby or far-off villages.

• Sequential Migration is a form of migration where migrant’s decision has not been
taken into consideration at all. Most of the children of migrating families can be
seen as best examples where they do not have any say in the decision made by their
elders. Another example is the wife who accompanies her husband.

3. urban-urban migration stream; Urban to urban migration is a common phenomenon both

in the highly urbanized parts of the world as well as in the less developed countries. People
move out from one urban place to the other. The motive is to find jobs to improve their
economic status. It is a common feature that large cities attract people from small towns in
their neighbourhood. This is especially true in the case of skilled workers. This practice is
known as step-wise migration. The first step is to move out from a village to a small town;
the second step is to move out rom a small town to a large city. Urban to urban migration
is due to multiple factors, economic as well as socio-cultural. It is the main channel of
labour supply to the fast growing city.

• Urban-urban migration can also be studied in the backdrop of ‘Step Migration’ as

propounded by Ravenstein:

✔ Small Town🡪 Cities 🡪 Big Cities/Metros

✔ Darbhanga 🡪 Patna 🡪 Delhi

4. urban-rural migration stream: Urban to rural migration is a kind of reverse flow. This is
so because large metropolises/mega cities in developed countries attain a high degree of
urbanisation, which widens the scope for absorption of rural labour in the informal sector
of economy. This also leads to the problems of housing due to over-congestion of cities
and the resultant problems of environmental pollution and poor health. This often forces
the migrants to return to their native villages. It may be noted that the rural areas in the
developing countries are generally underdeveloped. They lack infrastructure facilities to
accommodate the rural poor. The story of developed countries is entirely different. It is
also termed as Counter-Urban Migration or Return Migration
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Theories of Migration
1. Everett S. Lee has emphasized the role of pull factors or incentives associated with the
destination areas, push factors or those associated with the areas of origin, intervening
obstacles such as ethnic barriers, distance, cost and the personal factors to explain the
migration of people from one area to another. The pull factor includes employment
opportunities in the cities and the push factor includes labour surplus with low productivity
in the rural areas, disguised unemployment and the exploitative relationships that exist in
the villages. This theory has been utilized to explain the rural-urban migration in India.

2. Labour equilibration model by W.A. Lewis (1954) and J.C.H. Fei and G. Janis (1964)
has also tried to provide an explanation for migration; the model works on the assumption
of a dual economy that of labour attempting to move out from subsistence, low or zero
productivity economy to the fast growth capitalist, urban sector with higher wages.
However, the critics suggest that labour productivity is not zero in the rural areas;
moreover, it is the structural factors relating to the mode of production, which lead to low
production rather than little work in the villages

3. Harris and Todaro considered migration to be a function of labour allocation in response

to the market demands, so that the demand and supply of labour are always in equilibrium.
According to this theory, labour mobility occurs in direct response to the expected wage
differential between rural and urban areas. The theory further elaborates that if wage
differential between the rural and urban sectors is in excess of equilibrium, the inter-
sectoral transfer will continue until there is equality. The theory goes on to say that given
higher wages in the urban areas, people would be attracted from low-income
underdeveloped regions in numbers much larger than the available employment
opportunities on the chance of getting a job. The assumption of this theory is that the
individual is a rational economic person interested in the maximization of profit or utility
and it is basically poor who migrate as attracted by the higher wages. The premise of this
theory is on the economic factor while the non-economic factors have not been given
adequate attention.

4. Sameul A. Stouffer has developed the hypothesis of migration and intervening

opportunities. He argued that degree of migration would be inversely related to the distance
between the two places as also the extent of intervening opportunities but directly related
to the opportunities in two places.

5. J. Clyde Mitchell has theorized the idea in a more comprehensive way. He has stated that
a single factor explanation of migration is totally inadequate and that listing all possible
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motivations is also not very useful. He has seen the need to link together and has related
the multiple causes in a logical framework and suggested a classification whose major
headings are “the nexus of a centrifugal tendencies” and “the nexus of the centripetal
tendencies” sub divided by social, psychological and economic factors

6. Rao (1986) has also pointed out that isolated variables cannot adequately explain the
reason for migration. Hence, he has taken the multi-dimensional approach for the analysis
of migration. In this way, Rao has identified the following key factors in the multi-
dimensional approach:
● historical development of the region; wider economic and political conditions, which
regulate and condition the nature of employment opportunities;
● economic and social conditions in the place of origin; at individual level
● level of skills, family circumstances, process of socialization and the personality
factors; and presence of the resource network such as social network, which acts as
the most effective channel of communication that favours decision making in
migration
Q-1. Which of the following statement is not correct?
(A) Migrants move from low opportunity areas to areas of high opportunity.
(B) Migration takes place in steps.
(C) Each rural-urban stream produces urban-rural counter stream, but the former one does not
dominate the latter.
(D) The choice of destination is regulated by distance.

Q-2. Natural growth of population is the outcome of the following:

I. Crude Birth Rate
II. Crude Death Rate
III. Migration
IV. Marriages
Codes:
(A) Only I
(B) Only III
(C) II & IV
(D) I & II

Q-3. Migration of labour from rural to urban areas is classified as which type of unemployment ?
(A) Seasonal Unemployment
(B) Structural Unemployment
(C) Disguised Unemployment
(D) Open Unemployment