In depth
The lockdown was declared on 25 March 2020 under the Disaster Management Act, 2005. It closed most economic activity and restricted movement, and activity was later allowed to resume gradually.
The Government, in the Economic Survey 2020-21, presented it as a strategy to slow transmission while health and testing capacity was built, and estimated lives and cases averted by comparing India with expected values for countries and States. The estimate depends on assumptions about what would have happened otherwise, and the sources reviewed do not include a separate verification.
The measure also had immediate effects on migrant workers, many of whom lost work and sought to return to home States. The Union stated in court that movement was initially restricted to contain spread, and that Shramik trains and road transport began later. The Supreme Court took the matter up on its own motion and issued directions. GDP fell sharply in 2020-21 in official provisional estimates, later subject to revision.
Because the pandemic and the lockdown overlapped, outcomes in health and in output cannot be attributed to the lockdown alone, and the choice of counterfactual drives most of the differences between assessments.