Safeguarded flow data sets from the 2011 Census

New flow data sets from the 2011 Census of Population are being made available by the Office for National Statistics for the first time today via the FlowData website and other sources. FlowData is part of the Census Support, a value-added part of the UK Data Service; the flowdata team are Oliver Duke-Williams and Vassilis Routsis, of the Department of Information Studies at UCL.

Flow data – also known as interaction data or origin-destination data – are a specialised form of data about flows of people between two locations. These include migration flows between an origin and a destination, and journey-to-work flows between a residence and a workplace.

One of the new features of these data for outputs from the 2011 Census is the use of differing levels of access to data, with a trade-off between the level of detail in the data, and the ease of access. Today ONS are launching the first set of safeguarded data sets, and additional safeguarded data will soon be added. Safeguarded data sets are more detailed than the existing (and future) open data, and require that the user registers, and signs a set of terms and conditions of usage.

Oliver and Vassilis will be discussing these data in a Census Service webinar on Dec 4th, 2014.

The data sets that are being launched by ONS today are:

Table No.	Origin geography Destination geography	Table Title Table Population
MF01EW_all	Output Area Output Area	Origin and destination of migrants All usual residents who were living at a different address one year ago
MF01NI_all	Small Area Small Area	Origin and destination of migrants All usual residents who were living at a different address one year ago
MF01EW_non_uk	Country Output Area	Origin and destination of international migrants All usual residents who were living outside the UK one year ago
MF01NI_non_uk	Country Small Area	Origin and destination of international migrants All usual residents who were living outside the UK one year ago
MM01CEW_all	Merged ward Merged ward	Origin and destination of migrants by age (broad grouped) by sex All usual residents who were living at a different address one year ago
MM01CNI_all	Ward Ward	Origin and destination of migrants by age (broad grouped) by sex All usual residents who were living at a different address one year ago
MM01CEW_non_uk	Country Merged ward	Origin and destination of international migrants by age (broad grouped) by sex All usual residents who were living outside the UK one year ago
MM01CNI_non_uk	Country Ward	Origin and destination of international migrants by age (broad grouped) by sex All usual residents who were living outside the UK one year ago

Using the table MM01CEW_non_uk as an example, one simple way of considering these data is to look at the (non-UK) origins from which most migrants arrived. The following table shows the number of wards (out of roughly 8,500 in England and Wales) in which a given country was the largest source of migrants. This is sorted by the number of wards involved: thus, Australia was the most common source of migrants from outside the UK in 897 wards; this is the largest observation of ‘modal’ origins – thhe table shows the ‘top 10′ cases. The data are based on individuals’ former usual residence: it does not necessarily mean that (for the first row of the table) these migrants were either Australian citizens or had Australia as their country of birth.

 

Origin country	Number of wards
Australia	897
Spain (including Canary Islands)	855
USA	795
Poland	780
Other EU accession countries	720
Germany	517
France	509
India	440
Other Middle East	388
China	230