In MAKE Vol. 15, George Dyson, who writes the Retrospect column, looked at the mortgage meltdown.
The roots of the current financial meltdown can be found in John von Neumann's model of general economic equilibrium, first developed in 1932. Von Neumann elucidated the behavior of an expanding, autocatalytic economy where "goods are produced not only from 'natural factors of production,' but … from each other," and he proved the coexistence of equilibrium and expansion using the saddle-point topology of convex sets. Some of his assumptions – such as that "the natural factors of production, including labour, can be expanded in unlimited quantities" and that "all income in excess of necessities of life will be reinvested" – appeared unrealistic to others at the time, less so now that Moore's Law and the zero-cost replication of information are driving the economy of today. Other assumptions, such as an invariant financial clock cycle, are conservative under the conditions now in play.
Von Neumann, who made seminal contributions to digital computing, left a number of distinct monuments to his abbreviated career, among them his Theory of Games and Economic Behavior (with Oskar Morgenstern) and his Theory of Self-Reproducing Automata (with Arthur Burks). Synthesis between these two regimes is now advancing so quickly that no unified theory of the economics of self-reproducing systems has been able to keep up. Periodic instability should come as no surprise. We may be on the surface of a balloon. Or in the saddle of a dynamic equilibrium – we hope.