It is generally impossible to design an ex post efficient mechanism for bilateral trading when the traders' valuations for an object of trade are private, there are no outside subsidies and the traders can refuse to carry out a transaction if they expect to lose money. The first two essays focus...

Geoeconomic fragmentation—the phenomenon of international transactions being increasingly restricted to politically aligned partners—creates risks for individual countries but also opportunities that some hope to seize by becoming “connector” countries. We formalize the concept of...