Eco 7800 Urban Economics Kristine K. Langenbucher Estimation and Recent Behavior of Urban Population and Employment Density Gradients Molly K. Macauley Journal of Urban Economics 18 (1985),
Eco 7800 Urban Economics Kristine K. Langenbucher Purpose monocentric Model density declines with distance to CBD negative exponential form for density gradients corrected version of Mills‘ method original version incorporated bias article updates Mills‘ estimates until 1980 bias is small if MSA data are used density gradients for employment sectors
Eco 7800 Urban Economics Kristine K. Langenbucher Review/Methodology Ddensity at distance u D 0 density at City Center rate at which D declines with distance Recall... N(k)population at distance k usable space (1) (2)
Eco 7800 Urban Economics Kristine K. Langenbucher Methodology (3) Generally true? Probably not finite density in outskirts D > 0 Integrating to infinity, assuming that density D = 0 at edge of MSA, we get N. For a relative measure we divide N(k) by N.
Eco 7800 Urban Economics Kristine K. Langenbucher Methodology Disparity to N: Small for typical values of and k, since density is small at the edge of a city Over time decreased disparity and k increased disparity Effects seem to even out
Eco 7800 Urban Economics Kristine K. Langenbucher Measuring the differences w/ biasw/ow/ biasw/o D0D0 D0D0 D0D0 D0D0 Baltimore Rochester Boston and D 0 between 1940 and 1980 bias relative small
Eco 7800 Urban Economics Kristine K. Langenbucher Employment density gradients ManufacturingRetailingServices Baltimore D0D Rochester D0D Boston D0D
Eco 7800 Urban Economics Kristine K. Langenbucher Summary 1)continuing decentralization of urban areas 2)decentralization slowed down over the years rate 1920 –1980: 0.005/a 3)employment sector: manufacturing gradient converged towards the mean population gradient outpaced by higher decentralizations rates of retailing and wholesaling in the 80s 4)average gradients for all sectors converge 5)convergence also across MSAs