Formation of cartels in large markets

The von Neumann-Morgenstern concept of solution is applied to nonatomic pure exchange markets consisting of a finite number of different types of trader, initially owning disjoint sets of goods. It is proved that if all traders of each type form a cartel and behave like a single (atomic) trader (their “representative”), then one gets solutions of the original market from those of the finite market of the representatives, and all solutions are obtained in this manner—i.e., the market must organize itself in cartels, and this will indeed be stable.