Timothy Williamson’s Modal Logic as Metaphysics is, among much else, a detailed and complex defense of the metaphysical view he calls necessitism, the view that necessarily everything necessarily exists (is something), that although it may be a contingent matter how things are, what things there are is entirely a matter of necessity. The majority of contemporary modal metaphysicians reject this...

Strikingly, Ogawa and Wildasin (2009) find that in a model with heterogenous jurisdictions, interjurisdictional capital flows, and interjurisdictional environmental damage spillovers, decentralized planning outcomes are equivalent to that under a single centralized planner. Taken to its extreme this result renders international agreements such as the Kyoto Protocol irrelevant. We first show the...