ABSTRACT
Alvin Roth [1996, p. 198] It must be admitted that in many areas of mathematical economics very substantial abstractions are being used, so that one can hardly speak of a good approximation to reality. But it should be remembered that, on the one hand, mathematical economics is a very young science and, on the other, that economic phenomena are of such a complicated, involved nature that farreaching abstractions must be used at the start merely to be able to survey the problem, and that the transition to more realistic assumptions must be carried out step by step.
