By introducing repo markets we understand how agents need to borrow issued securities before shorting them: (re)-hypothecation is at the heart of shorting. Non-negative amounts of securities in the box of an agent (amounts borrowed or owned but not lent on) can be sold, and recursive use of...

This paper examines a set of necessary and sufficient conditions under which equilibrium involves mixing multiple types of workers in cities. Multi-skilled cities emerge if workers gain more from labor complementarities than they lose if they cannot consume their most preferred local amenities....

Inspired by the current debate over the future of the monetary union in Europe, this paper provides a simple model for the determination of the conditions of survival of the common good, which requires the creation of an effective fiscal union. We highlight the importance of institutional design...