TISS migration report, Mumbai demographics spark political firestorm

A report released by the Tata Institute of Social Sciences (TISS) has become the centre of an intense political and academic dispute, with social media users, politicians, and scholars sharply divided over its claims about illegal immigration and demographic change in Mumbai. Titled Illegal immigrants to Mumbai: Analysing socio-economic and political implications, the interim study is based on surveys of around 200 households in Mumbai’s slum clusters.

The report focuses mainly on undocumented migrants described as Bengali-speaking Muslims, including those allegedly from Bangladesh and the Rohingya communities. Although presented as a preliminary academic exercise, the report rapidly escaped scholarly confines and entered the political arena.

The controversy has been amplified by the report’s release just ahead of the Maharashtra assembly elections, leading critics to argue that its conclusions were primed for political mobilisation rather than careful policy discussion.

Key claims on migration, demography

Authored by a team led by TISS pro vice-chancellor Shankar Das and assistant professor Shouvik Mondal, the report argues that undocumented migration is reshaping Mumbai’s social, economic, and electoral landscape.

It claims that Mumbai’s Hindu population has declined steeply over recent decades, while the Muslim population has grown rapidly, projecting further demographic shifts in the coming decades. These changes are attributed to sustained migration and higher birth rates among migrant communities. The study further alleges that such population movements have placed severe strain on housing, infrastructure, and civic services in a city already grappling with extreme density.

The report also links undocumented migrants to organised crime, smuggling networks, drug trafficking, and even terrorism, while accusing political parties of exploiting migrant settlements for electoral gain. It claims that several assembly constituencies now have migrant-majority populations and alleges the large-scale procurement of identity documents through informal networks, enabling what it describes as ‘shelter politics’ in slum areas.

Political uptake, official reactions

The report was quickly seized upon by several BJP leaders and right-leaning commentators, who described it as confirmation of long-standing claims about demographic manipulation and illegal immigration in the capital of Maharashtra. On social media platforms, excerpts from the study were widely circulated as evidence of an existential demographic threat.

Senior political figures cited the report while calling for stricter enforcement against undocumented immigrants and revisions of voter rolls. Supporters framed the findings as a wake-up call, arguing that unchecked migration could alter electoral outcomes and undermine national security.

The study’s conclusions were repeatedly referenced in political statements and online debates, transforming an interim academic report into a tool of electoral and ideological contestation.

Academic backlash, methodological concerns

The report also provoked an intense backlash from within academia. More than 100 scholars, researchers, and activists signed a public statement condemning it as methodologically unsound, biased, and inflammatory.

Critics argue that a sample size of 200 households is wholly inadequate for drawing conclusions about a megacity the size of India's financial capital city. They also point to inconsistencies in demographic data, noting that official census figures do not align with several claims made in the report. Projections are criticised as speculative, with no transparent explanation of the models or assumptions used.

Particular concern has been raised about the report’s language, which opponents describe as non-academic and prejudicial. Terms linking migrant communities to ‘devastation’ and security threats are seen as starting from ideological conclusions rather than empirical inquiry. Several scholars have also questioned the absence of peer review and the timing of the report’s release during an election season.

Broader context, unresolved questions

Mumbai’s growth from a mid-20th-century port city to one of the world’s largest urban agglomerations has always been driven by migration, both internal and cross-border. Critics of the TISS report argue that it ignores this historical reality and fails to distinguish between structural urban challenges and communalised narratives.

They also warn that such studies risk normalising suspicion against entire communities while deflecting attention from governance failures, housing shortages, and labour market dependence on migrant workers.

With no formal retraction or revision announced, the report continues to circulate widely online, symbolising a deeper tension between academic responsibility, political opportunism, and the volatile politics of demography. Whether it leads to substantive policy reform or remains a flashpoint in India’s culture wars remains an open question.