Market games with differential information and infinite dimensional commodity spaces: the core (*)

We provide an alternative proof of the existence of core allocations in exchange economies with differential information and infinite dimensional commodity spaces. We also identify a critical feature of information sharing rules that ensures nonemptiness of the core. In essence, the only condition we require on the sharing rules is that profitable "insider trading" be prohibited. In the absence of insider trading, balancedness is guaranteed and core nonemptiness follows.