India launched its first census since 2011 this week, beginning a yearlong effort to count 1.4 billion people that will cost $1.2 billion and involve over 3 million workers. The results will determine how political power and welfare benefits are distributed across the world's most populous nation over the next decade. This marks India's first fully digital census, with residents able to submit information online in 16 languages.

The census comes five years late due to the Covid-19 pandemic and represents the first opportunity to collect caste data since 1931. The government's decision to include caste information, after initially opposing it under pressure from opposition leaders, has reignited debates about affirmative action policies. The data will influence how India reserves government seats and educational opportunities for historically disadvantaged groups. For the first time, the census will separately count nomadic and seminomadic tribal communities.

Beyond social policy, the census will redraw India's electoral map by aligning parliamentary seats with population size. States with faster population growth could gain seats at the expense of those that implemented successful population control measures. The results will also inform a 2023 law reserving one-third of parliamentary seats for women, though it remains unimplemented. The final data is expected in 2027, with implications lasting through the next decade.