2 Amson (1974) catastrophic model' of
His method is interesting (and more in the spirit of some of the meso applications described in the next chapter). He does not go for a potenti a1 functi on di rect ly, nor even, as is the case with most of the macro examples, for a direct representation of catastrophe geometry in canonical form (two control variables implies a cusp catastrophe and so on), but he seeks ways of specifying the equilibrium manifold of the three variables. Thus, the next step in the argument is to review briefly his four alternatives for 'urban laws':
His first possible law is:
p = KilT where K is a constant. This simply says that rental is proportional to density times opulence. This can also be written in the form
p. + = Kil ( 4.2)
which takes rental times average space occupied to be proportional to opulence.