The literature provides two polar explanations for the variety of products of quantities offered on the market. Either this variety results from the number of firms, each of which supplies a single product or quality. Or else there is a monopoly offering a variety of products, that is, choosing...

[eng] The influence of economic analysis on public policy : rise or decline ? . . This article describes the French experience concerning the influence of economic analysis on public policy decisions. Whereas economic analysis plays a well established role for the preparation of macroeconomic...