Note on District Concordance

Given that districts are constantly revised and redrawn by states, with new districts added or existing districts redrawn, the district data becomes inconsistent and incomparable across years, if no action is taken to standardise the data. There were 593 districts as of census 2001, rising to 640 districts as of census 2011. The periodic labour force survey (PLFS) of the National Sample Survey conducted in 2017-18 uses 646 districts, which itself is an underestimate of the number of new districts formed as of that year. To ensure comparability of district-level data across years, the CEDA portal displays all data concorded and rebased to districts as they existed at the time of the 2011 census. Data for districts that existed before 2011 (and were split or recombined as of 2011), or data for districts formed after 2011, are reweighed to corresponding 2011 districts using population as a weighing factor. Download the pdf file to understand the fundamentals of district concordance.