We reassess the well-known "narrow-but-deep" versus "broad-but-shallow" trade-off in international environmental agreements (IEAs), taking into account the principal-agent relationship induced by the hierarchical structure of international policy. To this end, we expand the modest coalition...

Recent contributions show that climate agreements with broad participation can be implemented as weakly renegotiation-proof equilibria in simple models of greenhouse gas abatement where each country has a binary choice between cooperating (i.e., abate emissions) or defecting (no abatement). Here...

Introductory notions -- The reference economic-ecological model -- Economic theory concepts -- Game theory concepts -- The global externality game (GEG) -- The dynamic GEG -- The dynamic GEG in numbers -- Coalitional stability in the GEG -- Policy and diplomacy: a GEG interpretation of the...