1. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 Estimation and Recent Behavior of Urban Population and Employment Density Gradients Molly K. Macauley Journal of Urban Economics 18 (1985), 251-260.

2. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 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

3. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 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)

4. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 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.

5. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 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

6. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 Measuring the differences 19401980 w/ biasw/ow/ biasw/o  D0D0  D0D0  D0D0  D0D0 Baltimore0.55587250.55586880.24218490.2321708 Rochester0.80448980.80449410.29130380.2913036 Boston0.30365820.28355180.20218580.1921212 0.670.660.250.24 and D 0  between 1940 and 1980 bias relative small

7. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 Employment density gradients ManufacturingRetailingServices 197219771972197719721977 Baltimore0.320.28 0.220.350.30 D0D0 335422941684114514101067 Rochester0.630.610.360.280.590.58 D0D0 90068604118982311831256 Boston0.200.280.240.220.380.35 D0D0 229740062270192330482832

8. Eco 7800 Urban Economics Kristine K. Langenbucher 12-09-2002 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