ON THE VARIABLE SHAPE OF THE FREE SPATIAL DEMAND FUNCTION*
通过分析证明，自由空间需求函数的形状在不同市场条件下会变化，凸性到凹性的转变可通过图形方法观察，关键因素包括凹性消费者需求、非均匀消费者密度和非线性运输成本。
ABSTRACT Analytical evidence is presented confirming variations in the shape of the free spatial demand function under different market conditions. For some simple spatial configurations of consumers, the transformation from convexity to concavity may be conveniently observed using graphical methods. The key criteria for concavity of the free spatial demand function are certain combinations of concave consumer demand, nonuniform consumer density, and/or nonlinear transportation costs. Although findings are confined to free spatial demand, similar variations may be expected to hold for the competitive case.