The East Is Changing: Demographic Transition In West Bengal And Northeast India – IMPRI Impact And Policy Research Institute

Insights
Ankita Ganguli

How falling fertility, ageing, youth migration and uneven urbanisation are reshaping India’s eastern frontier

India’s demographic debate is often reduced to a single question: is the population rising or falling? That question is increasingly inadequate for West Bengal and Northeast India.

The more important questions are now different. Where are families becoming smaller? Which districts are ageing first? Why are young people leaving some states while a few cities absorb ever-larger shares of the working-age population? What happens to villages when educated youth move away? And how should borderland mobility be studied without turning every demographic change into a claim about undocumented immigration?

West Bengal and the eight northeastern states occupy one of India’s most diverse demographic regions. They include the Kolkata metropolitan system, the rapidly growing Guwahati urban region, remote hill settlements, tea-producing districts, tribal-majority areas, river islands, border towns and climate-vulnerable zones such as the Sundarbans and the Brahmaputra valley. Their demographic futures will therefore not follow a single path.

The central challenge is no longer population growth alone. It is the growing mismatch between where people are born, where they study, where they find work and where they eventually grow old.

One Region, Several Demographic Transitions

Demographic transition refers to the long-term movement from high birth and death rates towards lower birth and death rates. But this transition does not occur uniformly.

The National Family Health Survey-5 (NFHS-5), conducted during 2019–21, estimated India’s total fertility rate at 2.0 children per woman- below the conventional replacement level of about 2.1. West Bengal’s rate was substantially lower at 1.6.

The Northeast presents a sharply varied picture. Sikkim had one of India’s lowest fertility rates, at approximately 1.1. Nagaland and Tripura were also below replacement level, while Assam stood at 1.9. Mizoram and Arunachal Pradesh were close to replacement level. Manipur was slightly above it, and Meghalaya, at approximately 2.9, remained one of the country’s highest-fertility states.

These differences matter. A region containing both Sikkim and Meghalaya cannot be governed through a uniform “population control” framework. Some states must prepare for shrinking child cohorts, school consolidation and accelerated ageing; others still require sustained investment in maternal health, reproductive choice, nutrition and education.

Fertility decline is not itself a crisis. It often reflects improvements in women’s education, child survival, access to contraception and household aspirations. The policy problem begins when falling fertility combines with large-scale youth out-migration, weak job creation and inadequate elder-care systems.

West Bengal: From Population Pressure to the Ageing Question

West Bengal is entering a more mature phase of demographic transition.

According to the India Ageing Report 2023, which draws on official population projections, people aged 60 years or above were estimated to constitute about 11.3 per cent of West Bengal’s population in 2021. Their share is projected to reach approximately 18.2 per cent by 2036. This would place the state above the projected national average of 15 per cent.

This shift has major consequences:

First, demand for healthcare will shift increasingly towards chronic diseases, geriatric medicine, long-term care, and home-based support. 

Second, smaller families may mean fewer relatives are available to provide unpaid care. 

Third, the ageing of rural populations may accelerate if younger workers continue moving towards Kolkata, other Indian metros or overseas destinations.

The issue is therefore not merely that West Bengal will have more older persons. It is that ageing may be geographically unequal. Kolkata and larger municipalities may offer hospitals and specialised services. At the same time, older residents in rural districts, the western plateau region, tea-garden areas and the Sundarbans may face greater difficulty accessing care, pensions and transport.

Ageing must consequently be treated as a district-planning issue rather than only a welfare-department concern.

The Northeast: A Young Region That Is Also Beginning to Age

The Northeast is generally described as young. That description remains partly true, but it can obscure the speed of change.

Official projections reproduced in the India Ageing Report 2023 estimate that the share of people aged 60 or above in the Northeast could rise from about 8.8 per cent in 2021 to 15 per cent in 2036. Assam’s elderly share alone is projected to increase from roughly 8.2 per cent to 13.6 per cent over the same period.

The regional average also conceals substantial state differences. Low-fertility states such as Sikkim are likely to age faster than higher-fertility Meghalaya. Tripura’s demographic structure differs from Arunachal Pradesh’s, while the migration experiences of Assam, Manipur and Mizoram are not interchangeable.

This creates a compressed policy timeline. Several northeastern states must continue addressing maternal and child health while simultaneously building systems for non-communicable diseases, disability support, old-age income security and community-based care.

In hill and remote districts, the delivery challenge is especially serious. A small and dispersed population raises the cost of maintaining health facilities, schools, public transport and digital connectivity. Demographic policy in such areas cannot be designed solely around population thresholds that work in densely settled plains.

Youth Migration: The Missing Half of the Demographic Debate

Demographic change is produced not only by births and deaths but also by migration.

The 2011 Census recorded more than 15 million persons classified as migrants in the northeastern states. A 2022 parliamentary reply clarified that approximately 93.8 per cent had moved from another place within the same state. This is an important qualification: the statistical category “migrant” includes movement associated with marriage, education, employment and changes of residence, and should not be automatically interpreted as cross-border immigration.

At the same time, research based on successive censuses shows an important outward movement of students and workers from the Northeast to Delhi, Bengaluru, Mumbai, Pune, Kolkata and other urban centres. Education, professional employment, hospitality, healthcare, retail and service-sector work are significant drivers.

This movement produces both opportunity and vulnerability.

Migrants gain access to education, employment and professional networks. Their earnings and remittances can support households in their home states. But sustained outward migration can also remove skilled young people from local labour markets, weaken the tax base of smaller towns and leave older parents with limited everyday support.

The critical policy question is not whether young people should migrate. Mobility is a legitimate part of economic freedom. The question is whether they are leaving by choice or because their home states offer too few pathways for higher education, research, enterprise and formal employment.

The objective should not be to prevent migration. It should be to create a credible right to remain, right to move and right to return.

Bengal as Both Destination and Departure Point

West Bengal occupies a distinctive position in eastern India’s migration system.

Kolkata remains an educational, medical, commercial and cultural centre for eastern and northeastern India. Siliguri functions as a gateway connecting the Northeast with the rest of the country and sits close to Nepal, Bhutan and Bangladesh. Industrial and service centres such as Durgapur, Asansol, Haldia and the expanding towns around Kolkata attract workers from within and beyond the state. A 2022 parliamentary reply based on Census 2011 data identified West Bengal as the leading destination for interstate migrants from the northeastern states, accounting for 39.56 per cent of that movement.

At the same time, West Bengal is also a major source of labour migration to other Indian states. This two-way movement complicates simple descriptions of Bengal as either a migrant-receiving or migrant-sending state.

Population change within Bengal is also being redistributed away from the old city-centred model. Research on the 2001-11 period found that new census towns accounted for a large majority of West Bengal’s urban growth. Many settlements became “urban” in demographic and occupational terms without immediately acquiring adequate municipal institutions, drainage, transport, housing regulation or public-health capacity.

The result is a form of hidden urbanisation: the population changes first, while governance catches up later.

Guwahati, Siliguri and Kolkata: The Emerging Eastern Urban System

The demographic future of the wider region will be shaped increasingly by a small number of urban corridors.

Guwahati operates as the Northeast’s principal metropolitan hub. Siliguri links the Northeast to mainland markets and border economies. Kolkata anchors the largest labour, education and healthcare market in eastern India. Shillong, Agartala, Imphal, Aizawl and Gangtok play smaller but important state-level roles.

As education and employment become concentrated in these cities, they attract a disproportionate share of young adults. This can produce a demographic double burden: congestion and housing pressure in destination cities, alongside ageing and institutional decline in places of origin.

Urban policy must therefore move beyond city limits. Transport, rental housing, hostels, public health and labour-market planning should be organised around functional urban regions and mobility corridors. A student leaving Manipur for Guwahati or a worker moving from North Bengal to Kolkata is part of a regional demographic system, not merely an isolated individual decision.

Borderlands: Evidence Before Assertion

West Bengal and the Northeast share international borders with Bangladesh, Bhutan, Nepal, China and Myanmar. Migration, ethnicity, citizenship and land rights consequently carry deep historical and political sensitivities.

These concerns cannot be dismissed. Border management, legal migration, refugee protection, trafficking prevention and the rights of indigenous and local communities are legitimate areas of public policy.

However, demographic analysis must maintain a clear evidentiary standard. Changes in population size, religion, language or settlement patterns cannot, by themselves, prove undocumented immigration. Such change may also result from fertility differences, internal migration, reclassification of settlements, displacement, marriage migration and variations in census reporting.

Conflating all mobility with illegality risks stigmatising border communities and weakening serious analysis. The correct approach is to combine reliable census data, civil-registration systems, border-management records and transparent research- while observing constitutional protections and due process.

Climate Mobility: The Next Demographic Variable

Climate change will increasingly influence where people live across eastern India.

In the Sundarbans, sea-level rise, salinity, cyclones, riverbank erosion and livelihood insecurity can encourage seasonal or longer-term migration. In Assam and other parts of the Northeast, floods, erosion and landslides repeatedly disrupt settlements and livelihoods. Mountain states face their own risks from extreme rainfall, slope instability and infrastructure pressure.

Not every person moving from a climate-vulnerable district can be labelled a “climate migrant”; decisions to move usually combine environmental, economic and social factors. Nevertheless, repeated loss of land, housing, crops or connectivity can gradually reshape settlement patterns.

Governments must therefore begin measuring climate mobility before it becomes a humanitarian emergency. District disaster plans, urban housing policy and social-protection databases should recognise temporary displacement, circular migration and permanent relocation as distinct categories.

The Data Problem- and the Opportunity of Census 2027

Much of India’s district-level demographic and migration analysis still relies on Census 2011. NFHS, the Sample Registration System and population projections provide essential updates, but they cannot fully replace a population census for local planning.

Census 2027 is therefore particularly important for West Bengal and the Northeast. The Government of India has scheduled its population-enumeration phase for February 2027, with the reference date fixed at 1 March 2027 for most of the country. The exercise is expected to collect demographic, socio-economic, cultural, fertility and migration information through India’s first digital census.

For the eastern region, the new census should help answer several unresolved questions:

• Which districts are losing working-age population?
• Where are elderly-only households increasing?
• Which census towns have outgrown their administrative capacity?
• How have student and labour-migration corridors changed since 2011?
• Where are climate stress and repeated displacement altering settlement patterns?
• How are fertility and age structures changing across rural, urban, hill, tribal and border districts?

The value of Census 2027 will depend not only on collection but also on timely publication of anonymised, district-level tables that researchers and state governments can use.

The Evidence Dashboard

What the Evidence Tells Us

Five broad conclusions emerge.

1. Eastern India is moving beyond the population-explosion framework.
Low fertility is already established across West Bengal and much of the Northeast.

2. The transition is deeply uneven.
Meghalaya’s demographic needs differ from Sikkim’s; Assam’s differ from Mizoram’s; Kolkata’s differ from the Sundarbans’.

3. Migration can accelerate local ageing.
A state may appear young in aggregate while particular rural districts lose young adults and age rapidly.

4. Urbanisation is occurring beyond statutory cities.
New and expanding settlements require municipal institutions before infrastructure deficits become permanent.

5. Demographic anxiety must not replace demographic evidence.
Borderland change should be investigated rigorously, not inferred from political narratives or isolated statistics.

The Way Forward

India needs an Eastern Demographic Transition Strategy built around six priorities.

1. Create district demographic observatories

West Bengal and each northeastern state should establish small analytical units linking census, health, education, labour, migration and climate data. District-level age structure- not merely total population- should guide the location of schools, hospitals, skill centres and care facilities.

2. Build a youth-retention and return ecosystem

States should expand quality higher education, apprenticeships, research institutions, creative industries, tourism value chains and remote-work infrastructure. Returning migrants should have access to enterprise credit, recognition of skills and professional networks.

3. Prepare now for ageing

Primary health centres need geriatric capacity, telemedicine and referral systems. Urban plans should include accessible transport and age-friendly public spaces. Rural policy should support home-based care, self-help groups, pensions and community workers assisting older persons who live alone.

4. Govern emerging towns before they become unmanageable

Settlement classification, fiscal transfers and municipal capacity should reflect actual population density and non-agricultural employment. Census towns and peri-urban areas require planned drainage, waste management, rental housing and public transport.

5. Create a humane borderland-mobility framework

Border governance should combine security with legal mobility channels, anti-trafficking cooperation, accurate documentation and due process. Indigenous rights and local cultural protections must be strengthened without collectively blaming mobile or minority populations.

6. Integrate climate mobility into development planning

States should map erosion-, flood-, cyclone- and landslide-prone settlements; make welfare benefits portable; protect displaced children’s education; and develop transparent, community-led relocation frameworks where adaptation in place is no longer viable.

Conclusion: The Question Is Not How Many, but Where- and With What Support

The demographic future of West Bengal and Northeast India will not be defined simply by whether population rises or falls.

It will be defined by the distribution of age, opportunity and mobility.

Some districts will have fewer children. Some will lose young adults. Some cities will absorb students and workers faster than they can house them. Some villages will age before adequate care systems exist. Border regions will continue to experience legitimate mobility and political anxiety. Climate stress will push movement into places already struggling with jobs, housing and public services.

The policy objective should therefore be clear:

Plan for smaller families.
Invest in young people.
Prepare for ageing.
Govern mobility humanely.
Build cities before congestion becomes destiny.
And replace demographic speculation with demographic evidence.

The eastern region’s demographic transition is not merely a population issue. It is a question of federal planning, human capital, social cohesion and the right of people to build secure lives- whether they stay, move or return.

Selected Sources and Further Reading

1. International Institute for Population Sciences (IIPS) and ICF. (2021). National Family Health Survey (NFHS-5), 2019–21: India Report. Ministry of Health and Family Welfare, Government of India. DHS Programme report.
2. International Institute for Population Sciences and United Nations Population Fund. (2023). India Ageing Report 2023: Caring for Our Elders- Institutional Responses. UNFPA India.
3. National Commission on Population, Ministry of Health and Family Welfare. (2020). Population Projections for India and States, 2011–2036. National Portal of India.
4. Office of the Registrar General & Census Commissioner, India. (2011). Census of India 2011: Migration Tables and Primary Census Abstracts. Census of India.
5. Press Information Bureau, Government of India. (2022). Migration of Youth from North-Eastern States, parliamentary reply dated 19 December 2022. PIB release.
6. Lusome, R., and Bhagat, R. B. (2020). “Migration in Northeast India: Inflows, Outflows and Reverse Flows during Pandemic.” The Indian Journal of Labour Economics, 63, 1125–1141. Open-access article.
7. Mistri, A. (2022). “Migration from North-East India During 1991–2011: Unemployment and Ethnopolitical Issues.” The Indian Journal of Labour Economics, 65, 133–153. Open-access article.
8. van Duijne, R. J., Choithani, C., and Pfeffer, K. (2020). “New Urban Geographies of West Bengal, East India.” Journal of Maps, 16(1), 172–183. DOI.
9. North Eastern Council. (2015). Basic Statistics of North Eastern Region 2015. Government of India.
10. Press Information Bureau. (2026). Census 2027: India’s First Digital Enumeration Exercise. PIB backgrounder.

About the Contributor

Ankita Ganguli is a public-policy researcher and practitioner with academic training in mathematics, English literature and public policy. She was selected among the top national participants of the Viksit Bharat Young Leaders Dialogue 2025, where she presented her ideas on gender sensitisation before the Prime Minister of India. Currently pursuing a Master’s in Public Policy at O.P. Jindal Global University, her research interests include governance, demographic change, gender, social development, foreign policy, and India’s eastern and northeastern regions.

Disclaimer

All views expressed in this article belong solely to the author. Population projections are estimates rather than enumerated counts. The article uses the latest nationally comparable data available at the time of writing; Census 2027 results may revise the demographic picture presented here.

Figure Captions and Sources

Figure 1. Fertility transition across West Bengal and Northeast India

Suggested placement: After the section “One Region, Several Demographic Transitions.”

Caption: Total fertility rate (children per woman) across West Bengal and the eight Northeastern states, NFHS-5, 2019-21. The map shows that low fertility is already established across much of the region, while Meghalaya remains a clear higher-fertility outlier. This variation demonstrates why a single population policy cannot fit the entire eastern region.

Data source: International Institute for Population Sciences (IIPS) and ICF. (2021). National Family Health Survey (NFHS-5), 2019-21: India Report and state fact sheets. Ministry of Health and Family Welfare, Government of India. https://dhsprogram.com/pubs/pdf/FR375/FR375.pdf

Figure 2. The ageing transition, 2021–2036

Suggested placement: After “West Bengal: From Population Pressure to the Ageing Question” or “The Northeast: A Young Region That Is Also Beginning to Age.”

Caption: Projected change in the share of the population aged 60 years or above. West Bengal’s elderly share is projected to rise from 11.3 per cent in 2021 to 18.2 per cent in 2036, while Assam’s is projected to rise from 8.2 per cent to 13.6 per cent. The published Northeast regional aggregate rises from 8.8 per cent to 15 per cent. Hatched states are deliberately not assigned invented state-level values.

Data sources:

Figure 3. Bengal-Northeast mobility and urban gateway system

Suggested placement: Between “Bengal as Both Destination and Departure Point” and “Guwahati, Siliguri and Kolkata: The Emerging Eastern Urban System.”

Caption: Key urban hubs and conceptual mobility corridors linking Northeast India with West Bengal. According to a 2022 parliamentary reply based on Census 2011, West Bengal was the destination for 39.56 per cent of interstate migrants from the Northeastern states. The dashed routes are analytical schematics and do not represent measured traffic volumes.

Sources:

Boundary reference for all three figures

District geometry is drawn from the open udit-001/india-maps-data collection, using Census 2011 and updated state files. https://github.com/udit-001/india-maps-data

The maps are analytical illustrations, not authoritative boundary or navigation maps.

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