We analyse the key determinants of umbrella effects, which arise when the price increase or quantity reduction of a cartel diverts demand to substitute products. Umbrella effects arise irrespective of whether non cartelists act as price takers (“competitive fringe”) or respond strategically...

The book studies the core of exchange and production economies in which agents are asymmetrically informed about states of nature. Information is modelled as part of the commodity space. When an agent joins a coalition, his information may change according to an information rule. It is shown...