The results are similar to those of the model with only transit
in the core. Most importantly, Proposition 4 holds with only minor modification: aggregate tolls from suburbanites cover the
cost of the land, A, devoted to roads and Samuelson rules continue
to determine the suburban land devoted to bridges and the
investment in core and suburban public transit. Core and sub-
urban public transit investments are fully financed by the single
confiscatory tax on the core’s aggregate differential land rent.
Details of the proofs are similar to those of Proposition 4 and left
for the reader to check but are available in the author’s supple-
mentary notes upon request.
4. Marshallian or other agglomerations in the core
In Section 3, private income, y, earned from work is given as
exogenous. A counter claim is that workers may be more produc-
tive because core-industries exhibit agglomeration effects.
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This – in addition to public transportation – may explain the job
concentration in the core. We modify the formulation to deal with
this. We assume that all suburban commuters drive-and-ride as in
Section 3.1.