1. Migration involves the movement of people across boundaries and is one of three components of population change, along with births and deaths. It is difficult to measure, model, and forecast compared to fertility and mortality. 2. Migrations can be internal within a country or region, or international across country borders. They can be voluntary or involuntary, and people who migrate are either immigrants or emigrants depending on their departure and destination points. 3. Migrations are selective based on factors like age, sex, family size, occupation, race, and education level. Young adults tend to migrate more than other age groups for jobs, while married people migrate less than unmarried people. Men also tend to migrate more than women.

1. Migrations
Along with births and deaths, migration is one of the three demographic components of
population change, and it has often been described as the most difficult to measure, model and
forecast. Unlike fertility and mortality, migration is not a single unique event in time and space,
but can repeat itself over the lifetime of an individual. Thus, the volume and type of migration
measured and analyzed depend on the definitions used to identify a migrant. So, migration can
be defined as
“The movement of people across the specific boundary involving change of residence for a
substantial period of time”
The temporary movement of people for the purpose of travel, tourism, pilgrimages, or the
commute is not regarded as migration, in the absence of an intention to settle in the new
location.
Migration has continued under the form of both voluntary migration within one's region,
country, or beyond and involuntary migration which includes the slave trade etc. People who
migrate into a territory are called immigrants, while at the departure point they are called
emigrants. Refugee’s population is that part of population who are seeking shelter or refugee.
Classification of migration is not an easy task as there exists an extreme diversity of migration in
cause, duration, distance, direction, volume, velocity, selectivity and organization. There may
be of seasonal, temporary, periodic, permanent, spontaneous, forced, impelled, planned,
internal, external, inter-regional, international, continental or inter-continental type migration.
DIFFERENTIAL MIGRATION
Migrations are age and sex selective. The most accepted migration differential is certainly that
of age, as young adults migrate first to their jobs. Fortunately, they adjust more easily to their
new environment than do other age groups. Among young population, males migrate first than
females. On the other hand, married people migrate less as compared to unmarried people. In
Most developed Countries (MDCs) short distance internal migrants are pre-dominantly female

2. while long distance internal migrants are pre-dominantly male; on the other hand, in Less
Developed Countries (LDCs) both internal and international migrants are pre-dominantly male.
Family size is also an important selective factor of migration. Today, in LDCs there are more and
more migration of families, looking for better houses, schools, social conditions and jobs.
Migration is also more common among certain occupation groups than others. Professional
classes are proportionally more migratory than either skilled or unskilled workers. Unemployed
persons tend to be more migratory than employed persons. Migratory selection also take place
by race, nationality and educational attainment, and in general the process of selection
depends more upon conditions at the destination than upon those at the place of origin, for
migration which as a strong push stimulus tend to be less selective than migration which is
mainly responsive to pull factors.
CAUSES OF MIGRATION
Causes of migration are varied and complimentary. It involves both the “push” and “pull”
factors both at the origin and destination of migrants. Bogue enlist 25 migration stimulating
situations for persons, 15 factors in choosing a destination, and 10 socio-economic conditions
which can stimulate or retard mobility among a population.
Push factors includes
Graduation; marriage; lack of marriage; employment offers; retirement; military service;
medical care; imprisonment; natural disaster invasion by outsiders; wanderlust; social
projection; forced movement.
Pull factors includes
Cost of moving; presence of relatives or friends; employment offer; physical attractiveness;
amenities; population composition; special employment facilities; knowledge; special
assistance; subsidies; information reputation; lack of alternative destinations.

3. Socio-economic conditions affecting migrations includes
Major capital investment; major business fluctuations; technological change; changes in
economic organization; provision for social welfare; migration propaganda facilities; regulation
affecting migration; tolerance of minorities of all types; migration policy.
These lists are not exhaustive. Other factors may be added like population pressure and
growth, the availability of land in an area of departure and destination etc.
1 INTERNAL MIGRATIONS
MEASURMENT
Direct measurement of internal migration is only possible in the countries where migration
question is posed at the census. However, some indirect measurement of migration are also
possible such as vital statistic method which estimate the total net gain or loss in population of
a community as a result of migration by subtracting total net natural increase from total inter-
censual change. We can also use survival ratio method which estimates the proportion of
population which should be expected to survive at the second census. Migrations can also be
measured by comparison of place-of-birth statistics with present residence.
Volume of migration in an area also called as gross migration which is the total of emigration
(from area of departure) and immigration (into area of arrival). Immigration rate is the number
of immigrants divided by total population at the destination multiplied by K in a given year. K is
constant and its value is 1000. Emigration rate is the number of emigrants departing from an
area of origin divided by total population per 1000 population. Net-Migration shows that the
net affect of immigration and emigration on an area’s population.
TYPES OF INTERNAL MIGRATIONS
SEASONAL MIGRATIONS
Nomadic populations usually engage in seasonal migrations. Pastoral nomadism is the
movement of human groups and their flocks or herds following the distribution of pastures.
Seasonal pastoral migrations need not entail nomadism.

4. PERIODIC MIGRATIONS
Include the staying of people, away from their permanent houses for periods of a few years and
returned periodically. Maximum earning is the major push factor behind such migrations.
RURAL-URBAN, URBAN-RURAL and INTRA-URBAN MIGRATIONS are generally the most
important form of internal migration, especially in countries experiencing industrialization and
rapid technological change. Urban-centers usually offer seductive amenities such as schools,
shops, and public-utilities etc. which are the major pull factors for rural urban migration. The
separation of workplace and residence causes inter-city migrations. Drifts of population from
one part of a country to another, from the less favored to more favored regions, are
widespread.
2 INTERNATIONAL MIGRATIONS
International migrations are of greater demographic significance than that of internal
migrations, as they mean either a gain or a loss in a country’s population. The twenty-first
century has been called “the age of migration”, essentially because there are more migrants in
the world today than ever before — about 232 million international migrants in 2013.
DETERMINANTS
Many of the determinants of urbanization are the same as for the internal migrations,
especially the economic motives. Standard of living is the basic determinant of international
migrations as people are migration to host countries in search for better livelihoods and jobs to
improve their standard of living. Some of the countries deploy special restrictive immigrations
measures so as to restrict the entry of certain ethnic groups which are considered undesirable.
International migrants are highly selective with regard to education and skills. For example,
highly skilled migrants represent an important component of international flows and their
movement primarily tends to take place between more developed countries and from a
relatively small number of middle-income or rapidly developing economies, such as China and
India, to a small number of more developed countries. Nevertheless, a solution to the ageing of
populations in the developed world is often seen to focus on encouraging the immigration of

5. workers who will not only fill vacancies in the labor force but also contribute to the tax revenue
to support the increasing number of retired people.
WORLD MIGRATIONS PATTERN
The global migration system has changed over recent decades with regard to the origins and
destinations, as well as the volume and types of migrants. Countries that were once origins of
migration became destinations of migrants and vice versa. The shift from Europe as a major
area of emigration, primarily to the Americas and Australasia, to a major area of immigration
over the course of the twentieth century is perhaps the most striking recent historical example.
At the beginning of the twentieth century a million migrants a year were leaving Europe mainly
for Northern America. In 2010, the European Union absorbed 1.2 million “permanent”
migrants, more than the number of permanent migrants to the United States (over one
million), which represents a very significant shift in the global migration system over the last
one hundred years.
CONCLUSION
Migrations meant differently for different countries. In LDCs, migrations act as a safety valve
and assists economic development. Managing and monitoring world migration pattern poses
serious challenges to policymakers and analysts alike, not least because of a continued lack of
timely and accurate data on population movements both long-term and short-term.
Nevertheless, global environmental change is indeed another factor that policymakers will have
to incorporate into attempts to manage migration even if those movements are most likely to
be short distance and short term. The greatest need is to take into consideration the long-term
shifts in mobility that the dynamics of population change imply. Successful policy is more likely
to result from planning for such expected global shifts in migration than from trying to regulate
or reverse them.