Overview

Data source: UK Census of Population (England and Wales)

Provision: 2011 only, information on geographical patterns of employment and travel to work distances

Update: every 10 years, the next census in England and Wales will be in 2021.

Questions you can ask of the data:

• How far do people travel to work in a particular occupation?
• Where do people in a particular occupation live?

Description of the dataset and provenance

Census statistics provide a detailed snapshot of the population and its characteristics, and underpin funding allocation to provide public services.

The LMI for All database includes specific data from the Census. Geographical patterns of employment and travel to work distances show how far people travel to work. This is derived by using the household home postcode, and the workplace postcode, and calculating the distance between them. Information on geographical patterns of employment and travel to work distances. Distances are calculated from postcoded Census data and calculated in kilometres. Derived distances that result in a distance travelled that exceeds 1200km are treated as invalid and a value is imputed. A distance travelled of 0.1km indicates that the workplace postcode is the same as the residential postcode.

Data are provided by:

• Occupation (SOC2010 4 digit categories)
• Geography, available for Output Areas, Lower and Middle Super Output Areas and the hierarchy of local government areas from wards to regions and nations

Details of the owner / curator

The Office for National Statistics (ONS) are responsible for running the survey.

Known quality issues with data

The census is the most complete source of information about the population. It is the only survey which provides a detailed picture of the entire population, and is unique because it covers everyone at the same time and asks the same core questions everywhere. This makes it easy to compare different parts of the country.

ONS uses complex statistical techniques to adjust the 2011 Census counts for those people missed by the census. The methods and quality assurance approach was researched and developed in consultation with academics, statisticians, demographers and users of census data. The result was a suite of methods to process, clean, adjust and protect the census results.

An overview of the quality assurance process with examples of how inconsistencies identified during the process were identified and resolved. These are documented in: Quality assurance of census population estimates.

Quality control processes

Statistical disclosure control has been applied to 2011 Census data to protect the attributes of an individual. The ONS has used two complementary strategies for protecting individuals while minimising damage to the results: targeted record swapping, and restriction of detail particularly at low level geographies. This ensures that the confidentiality of the individual is protected.

Accuracy of data

The 2011 Census estimate for the England and Wales population had a 95 per cent confidence interval width of plus or minus 0.15 per cent (plus or minus 83,000 people). Census estimates used the Census Coverage Survey to measure coverage of the census and to provide estimates of the population, including people missed by the census. A basic requirement of any estimate is a measure of its precision or uncertainty. A 95 per cent confidence interval, which provides a measure of accuracy, can be interpreted as the interval within which 95 times out of 100 the true value will lie if the sample were repeated 100 times.

Frequency of update

Does the data underlying the API change over time?

The Census of Population is conducted every 10 years, so the data will not change until the next Census in 2021.

Will the data go out of date?

The data are as accurate as they can be at the time they are produced.

Does the data you capture change on at least a daily basis?

No – see above

What type of dataset series is this?

Not applicable

Is a feed of changes made available?

No, see above

How frequently do you create a new release?

Every 10 years

What is the delay between creating a dataset and publishing it?

Once the data have been processed they can be uploaded to the LMI for All database.

Do you also provide dumps of the dataset?

No

Will the data be corrected if they contain errors?

Yes

Disclosure and confidentiality

The Department for Education complies with all applicable Data Protection laws in the UK.

The geographical patterns of employment and travel to work distances data included in this database are non-disclosive.