POPULATION MIGRATION

Essence and Theoretical

Approaches to Its Study

An interdisciplinary exploration of human mobility — its definitions,

drivers, patterns, and the major theoretical frameworks used to understand it.

Geography & Population Studies

What Is Population Migration?

Definition

Population migration is the movement of people from one place to another with the intent to settle, temporarily or permanently. It involves crossing administrative, political, or geographic boundaries and results in a change of usual residence.

Spatial Scope

Internal migration occurs within a country (rural–urban); international migration crosses national borders.

Duration

Ranges from temporary (seasonal, circular) to permanent resettlement. Duration shapes legal status and integration.

Voluntariness

Voluntary migration is self-initiated; forced migration is driven by conflict, disaster, or persecution.

Types & Forms of Migration

Labour Migration

Movement for employment — the dominant form globally. Includes skilled, unskilled, and seasonal workers.

Forced Displacement

Refugees, asylum seekers, and IDPs fleeing conflict, persecution, or environmental catastrophe.

Family Reunification

Movement to join relatives already settled abroad; a major driver in developed countries.

Student / Lifestyle

International students, retirees, digital nomads — voluntary mobility tied to personal choice.

Environmental

Displacement driven by climate change, natural disasters, sea-level rise, and resource scarcity.

Irregular Migration

Movement without legal authorization; raises complex questions of rights and governance.

Push–Pull Theory (Lee, 1966)

ORIGIN — PUSH FACTORS

• Poverty & unemployment
• Political instability / conflict
• Environmental degradation
• Lack of services / education
• Natural disasters

​

→

MIGRATION

DESTINATION — PULL FACTORS

• Higher wages & employment
• Political freedom & safety
• Better education & healthcare
• Family & social networks
• Economic opportunity

​

Lee also identified intervening obstacles (distance, immigration policies, cost) that filter migration decisions.

Economic Theories of Migration

Neoclassical Theory

Macro (Harris & Todaro) / Micro (Sjaastad)

1. Migration driven by wage differentials between regions/countries.
2. Workers move from low-wage to high-wage areas until equilibrium.
3. Micro level: individual cost–benefit calculation of expected gains.
4. Predicts migration flows will cease when wage gaps close.

New Economics of Migration

Stark & Bloom (1985)

1. Migration is a household strategy, not just an individual decision.
2. Aims to diversify income and reduce household risk.
3. Relative deprivation matters — comparison with local peers.
4. Remittances are central to family welfare back home.

Critique: Both frameworks focus on rational economic actors and underemphasize social, cultural, and structural constraints.

Structural & World-Systems Theories

World-Systems Theory (Wallerstein / Sassen)

Migration flows from peripheral (developing) to core (developed) countries follow historic ties of colonialism, trade, and capital investment. Global capitalism creates labor demand at the core and surplus labor at the periphery. Saskia Sassen extended this to show how global cities actively recruit migrant workers for both high-skill and low-wage service jobs.

Dual Labour Market Theory (Piore, 1979)

Advanced economies have a permanent secondary sector of low-wage, insecure jobs that natives reject. Migration fills this structural demand regardless of wage levels at origin. Employers and states actively recruit migrants.

Dependency & Cumulative Causation (Myrdal / Massey)

Once migration begins, self-perpetuating mechanisms emerge: social networks lower costs, relative deprivation increases, and communities become dependent on remittances. Migration becomes structurally embedded.

Network Theory & Social Capital

Why do migration flows persist long after the initial economic conditions that started them?

Migrant Networks

Personal ties between current/former migrants and potential migrants at origin. They convey information, provide assistance, and reduce risks — effectively subsidising migration.

Social Capital

Networks give migrants access to jobs, housing, credit, and emotional support. The value of these ties accumulates over time, making migration increasingly accessible.

Chain Migration

Each wave of migrants lowers barriers for the next, creating self-sustaining 'chains' that link specific origin communities to specific destinations.

Transnationalism

Migrants maintain simultaneous attachments to both origin and destination societies — sending remittances, voting, shaping culture across borders.

Policy implication: cutting off receiving-country opportunities does not automatically stop migration — networks sustain it.

Contemporary & Emerging Approaches

01

Transnational Migration Theory

Migrants live lives that span borders simultaneously. Glick Schiller et al. (1992) argued migrants create social fields connecting origin and destination — reshaping both societies.

02

Intersectionality & Gender

Migration is experienced differently by class, gender, ethnicity, and age. Feminist approaches reveal hidden feminisation of migration and care economy dynamics.

03

Migration Systems Theory

Focuses on stable, structured links between countries. Kritz et al. (1992) examine how historical, economic, political, and cultural ties shape and sustain migration corridors.

04

Climate & Environmental Migration

The 'environmentally displaced person' concept is growing in importance. Links between slow-onset climate change, resource scarcity, and migration decisions are now central to policy.

No single theory fully explains migration — contemporary scholarship is increasingly integrative and multi-scalar.

Global Migration at a Glance

281M

International migrants

worldwide (IOM 2023)

3.6%

Share of world

population on the move

$831B

Global remittance flows

to low/middle-income countries

117M

People forcibly displaced

by conflict & persecution

Major Migration Corridors (millions, approx.):

KEY TAKEAWAYS

Theoretical Synthesis

1

Migration is multidimensional —

It cannot be reduced to economics alone — culture, networks, coercion, and environment all matter.

2

Theories are complementary —

Push–pull, neoclassical, network, and world-systems theories each capture different aspects of reality.

3

Context is decisive —

The same theory may explain migration in one corridor but fail in another — empirical testing is essential.

4

Migration shapes both worlds —

Origin and destination societies are simultaneously transformed by migration flows and remittances.

Population Migration: Essence and Theoretical Approaches