The causes of Long-term Urban and Neighbourhood Change

Geoffery Meen

University of Reading

The study arises from a stylised fact: although individual households may move from deprived areas as they become richer, the overall spatial patterns of neighbourhood segregation and poverty in the UK appear to have changed little over the course of the last thirty years, despite the thrust of government policy to improve spatial mixing. Consequently in order to find evidence of change, it may be necessary to consider much longer periods of time, dating back to the 19th century. The availability of census and other records from the mid 19th century and progress in historical GIS techniques now makes this feasible, although still extremely time consuming. Arguably, urban change takes place in response to four types of shocks:

(i) Exogenous innovations: examples are wars, acts of terrorism, acts of God.
(ii) Policy innovations: these include major infrastructure changes, e.g. new road networks, new social housing estates, slum clearance and major regeneration schemes.
(iii) Technology innovations: for example, the Industrial Revolution, powered flight, motorised transport.
(iv) Endogenous change: migration is the most notable.

In some cases, change may not be gradual or monotonic, but may take place in discrete jumps, since, with the exception of (iv), most of these events occur irregularly. Furthermore, shocks may have to be very large to have any discernible impact and even large shocks may be mean reverting. The paper is concerned with three issues. First, the theory of urban dynamics allowing for spatial interactions, which may generate properties of complex systems; second, the extent to which the social statuses of neighbourhoods have converged over the last 120 years or whether persistence and spatial lock-in exists even over these very long periods of time; third, the effect of shocks on urban patterns. In the light of the above, slum clearance programmes and war-time bombings are considered.