Activities for the next decennial Census of India falls due in 2021.
It is high time that India takes note of the transformation in census methods elsewhere in the world.
What is the recent development?
There has been a remarkable transformation in census methods elsewhere in the world, mostly in Europe, in last two decades or so.
The traditional census approach adopts the questionnaire-based method.
Instead, attempts are being made to use data from various administrative data registers.
Mostly, data from government sources are used, to produce useful statistics.
What are the noteworthy methods elsewhere?
Austria - The traditional census involves a high burden for respondents, and a huge cost (€72 million).
In 2000, the Austrian government decided that the 2001 census would be the last traditional one.
Consequently, a register-based “test census” was conducted in 2006, successfully testing the methods, data procedures and use of registers.
The first complete register-based 2011 census had no burden for respondents, and the cost declined to €10 million.
Most of the data were already available in several registers like the Integrated Data Bases for persons, families, households, buildings and dwellings, and locations of work.
Data was also available from municipalities, geo-information statistical databases and interactive maps.
The difficult task of combining all large registers was done by using a special identification number for persons.
At times, same variables featured in many registers.
Variables not in any register, such as “language mostly spoken” and “religion”, were collected by suitable sample surveys.
Germany - Germany conducted a nationwide census in 2011 after a 20-year gap.
This first register-based census was a multiple-source, mixed-mode method to collect data from administrative registers.
They include population registers, full enumerations and a sample survey.
Others - In Swiss too, since 2010, information is primarily drawn from population registers and supplemented by sample surveys of about 5% of the population.
Nordic countries such as Norway, Finland, Sweden and Denmark have a long tradition of using administrative registers for producing official statistics.
They now conduct population censuses using administrative data registers rather than through a nationwide survey of households.
Netherlands has held virtual censuses since 1981, using the Population Register and surveys.
Estonia, perhaps the most advanced digital nation in the world, used a combined census methodology using several registers along with an e-census in 2011.
However, Estonia is now moving towards a completely register-based census for 2021.
UK would replace the decennial census beyond 2021 by statistics produced by more regular and timely administrative data.
Greenland in North America and Singapore and Bahrain in Asia are also making effective use of registers for their censuses.
What lies ahead for India?
India should think beyond the traditional questionnaire-based approach.
While the country’s 2011 Census cost about Rs 22 billion, the 2021 Census could cost about Rs 46 billion.
Instead, billions of rupees can be saved by making use of the administrative data of several available registers instead.
Nevertheless, it would be a challenging task for a country like India with 1.3 billion.
But, India does have the statistical and technological expertise.
Several government registers can be combined along with tax, hospital and educational records to produce statistics similar to the census.
The loss of information, if any, should be minimal, and can easily be compensated by suitable sample surveys.
