The ONS recently
released the latest UK Travel to Work Areas, modelled using data from the 2011 Census – a staple for all local economy experts.
Travel to Work Areas (TTWAs) are developed to show areas where most people both live and work, hence areas in which most of the commuting occurs within their boundaries. In practice, they consist of
lower layer super output areas grouped together
‘in such a way that most workers living in an area also work in the same area and most people who work in an area also live there’.
While defining them proves to be a lengthy statistical and convoluted exercise, TTWAs draw an interesting and important picture of the UK’s labour market dynamics.
Figure 1: UK 2001 and 2011 Travel to Work Areas – ONS Geography
(
see a bigger version of the 2001 map and the 2011 map)First, there are 15 fewer TTWAs in the 2011 edition compared to 2001. As a consequence, their average size has increased. This is in line with a long-standing trend that has seen the number of TTWAs steadily decline since 1981 (there were 334 in 1981, 308 in 1991, 243 in 2001 and 228 in 2011).
A combination of variables could potentially be at play here, for example, better transport links, stronger town centres, higher house prices in urban areas and Green Belts displacing urban sprawl. Do fewer-and-larger TTWAs mean that people have to travel more to get to work or do they simply reflect a personal choice?
Crucially, strong inferences made purely on the basis of TTWAs can be dangerous and misleading. For example, people may be being displaced due to unaffordable housing or constraining planning obligations or because they are choosing to live further afield now that transport has improved.
Secondly, a quick look at the 2011 map suggests that London’s employment reach has shrunk since 2001. At the same time, the 2011 London TTWA has grown in absolute terms in both the number of residents in work and the number of jobs. Unsurprisingly, the capital city’s
gravitational pull on its surroundings is powerfully stark.
London’s apparent geographical contraction – despite its growth in employment numbers – is easily explained. To determine a TTWA, 75% of the workers in an area need to be living in that area. However, this criterion can be relaxed and reduced to 66.7% in areas with at least 25,000 resident workers, in order to restrain “the size of the largest TTWAs and in particular the one centred on London”. In fact, as visible below, all of London’s neighbouring TTWAs (except Cambridge) were determined following the relaxed criterion.
Figure 2: Share of employed residents who work locally, London – NLP analysis
In fact, the same applies to Manchester, which since 2001 has also increased its employment footprint by expanding westwards into the TTWAs of Bolton and Rochdale & Oldham.
Figure 3: Share of employed residents who work locally, Manchester – NLP analysis
And Newcastle…
Figure 4: Share of employed residents who work locally, Newcastle upon Tyne – NLP analysis
While on the face of it relaxing one of the criteria does not seem that contentious, it actually leads to underestimations of the significant pull of urban economies across the UK.
However, regardless of this methodological issue, TTWAs have the power to start a conversation about appropriate and functional economic areas. For example, as individual TTWAs grow and councils’ finances shrink, should public money be spent and administered in the areas where the majority of people live and work (i.e. travel to work areas)? To what extent could this contribute to the case made in the decentralisation agenda?
