Residential Density Patterns in London—Any Role Left for the Exponential Density Gradient?

In this paper the theoretical economic foundations of the exponential function is reviewed, prior to an investigation of whether the familiar flattening of density gradients may be easily explained by the factors and trends most often used in practice. These are the effect of real income growth on residential land consumption and of possible improvements in speed as well as cheaper fares in the means of commuting. Density gradient estimations are carried out for London, with use of data from wards and London boroughs. A variety of different functional forms are tested, and the possibility is examined of a density discontinuity generated by the River Thames. Weighted regression techniques are used to correct for biases caused by wide variation in the areas used for observations. Finally, the actual variation of real incomes together with real fuel prices and fares on public transport in London are studied. It is concluded that these factors do not explain the observed flattening of density gradients, so that explanations must rest in other directions such as vintage factors and employment subcentres.