We address economies with asymmetric information where agents are not perfectly aware about the informational structure for coalitions. Thus, we introduce solutions that we refer to as risky core and ambiguous core. We provide existence results and a variety of properties of these cooperative...

We consider infinite horizon economies with incomplete financial markets. Securities are in positive net supply and may be infinite-lived. We establish existence of equilibria by requiring borrowing constrains instead of portfolio restrictions..

In sequential economies with finite or infinite-lived real assets in positive net supply, we introduce constraints on the amount of borrowing in terms of the market value of physical endowments. We show that, when utility functions are either unbounded and separable in states of nature or...