Abstract
Two issues related to power have received particular attention by economists: the power over companies and the power over markets. The first issue concentrates on the changes in the structure of ownership and control in the economy. It is concerned not with the exercise of power per se, but rather with changes in the ability to exert power. The second issue deals with actual influence, i.e. with the way in which power is wielded. It is concerned with firm behaviour and the way firms affect competitive conditions and prices in a market or a set of markets. This is the theme of this book.