We investigate the role of networks of military alliances in preventing or encouraging wars between groups of countries. A country is vulnerable to attack if there is some fully-allied group of countries that can defeat that country and its (remaining) allies based on a function of their...

Tradable White Certificates (TWC) schemes, also labelled Energy-Efficiency Certificates schemes, were recently implemented in Great Britain, Italy and France. Energy suppliers have to fund a given quantity of energy efficiency measures, or to buy so-called "white certificates" from other...