We consider a principal who allocates an indivisible object among a finite number of agents who arrive on-line, each of whom prefers to have the object than not. Each agent has access to private information about the principal's payoff if he receives the object. The decision to allocate the...

Under full substitutability of preferences, it is known that a competitive equilibrium exists in trading networks, and is equivalent to (chain) stable outcomes. In this paper, we formulate the problem of finding an efficient outcome as a generalized submodular flow problem on a suitable network....

The fear of contracting a serious illness caused by a contagious disease limits economic activity even after reopening. Widespread testing alone will not alleviate this problem. We argue that targeted testing in concert with targeted transfers is essential. We propose a model with these features...