The UK census offers researchers unique data about the UK population that can’t currently be derived from other government sources, says Dr Oliver Duke-Williams, Service Director for the Census at the UK Data Service.
His views come after a number of news outlets ran articles last month based on comments from Sir Ian Diamond, the newly-appointed National Statistician, who said he was looking at alternatives to the decennial census delivered to every UK household.
The BBC reported that the 2021 census may be the last one because Sir Ian is exploring whether much of the data currently reported in the census could be obtained from a range of other administrative data sources, such as GP registrations, council tax records and driving licences. This would be supplemented by information gathered through surveys, the BBC said.
Dr Duke-Williams said: “If we are interested in overall population numbers, perhaps by age and sex, then we can look to administrative data to provide us with good estimates both nationally and for small areas, but there are some characteristics where the traditional census offers us valuable data that can’t really be found elsewhere. And, while administrative data can provide the basis for robust statistics, it would be much less reliable in providing data which could be used to explore the relationship between things.”
The UK Data Service holds and enables access to aggregate, boundary, flow and microdata from the last six censuses from 1961 through to 2011 and will be supporting the government in providing access to the census data for 2021. For an update on what is planned for the 2021 census and how UK Data Service users can make use of it, it’s still not too late to sign up to our specialist webinar planned for Friday 6th March at 11am.
One example of the valuable data generated by the census is the data on informal care, where, for example, unpaid care might be provided to an older or dependent person by someone with whom they have a social relationship.
Dr Duke-Williams said: “There is a question on the census about informal care and this is an important dynamic in society. We know about the numbers of people receiving formal care but nowhere else can we find out about informal care arrangements in a detailed way, across the whole country”.
Another area where the census provides unique data is around household structure and the family relationships within a household.
“Most administrative data is targeted at the individual,” continued Dr Duke-Williams.
“We might know that an individual has a partner or children but little else beyond that. The census asks households to list everyone living in a household and to give details of their relationship to the head of the house. It allows us to see details about families that might otherwise be non-obvious, especially when it comes to multi-generational families.”
Dr Duke-Williams says the data the Census provides on how people journey to work is also valuable and could be used to inform transport policy.
“There is a series of questions in the census that ask where you live, where you work and how you get to work. We don’t have any comprehensive information on this from any other source.
“Tax information exists for working people, but that doesn’t necessarily tell us where people work, so much as the name and some details of their employer. In contrast, the census collects information on workplace location at a very detailed level. More significantly, the census also collects information on the mode of transport used to get to work, and – whilst travel surveys do exist – there are no other nationally comprehensive, detailed data sources on method of travel to work.
“That level of detail is vital if we want to do transport demand modelling, which might help us to move as a society towards more environmentally friendly travel behaviour”
He added: “It’s clear the census has its drawbacks: it only takes place once every ten years, so there are good reasons to explore if we can do things better.”
The big change for the 2021 census is that most households are expected to complete it online, which, in itself poses some challenges, especially for those households who either do not have the technology and/or the skills to complete it online.
Dr Duke-Williams said: “A decision on whether to shift away from the census is expected in 2023, once the results of the 2021 census have been evaluated. At the same time, the ONS is undertaking a huge body of work, aggregating administrative data, so these estimates can be compared with the census data.”