Parliamentary cabinets are supposed to be collective bodies, taking their decisions on the basis of agreements among all the members. Yet much has been made of the growth of the role of prime ministers, not just in Britain, but all over Western Europe. Much has also been made of the trend towards letting cabinet decisions be taken by committees or even by individual ministers. These are the issues which this study examines, on the basis of the replies of over 400 cabinet ministers across Western Europe. The result is an empirical analysis of a subject on which what has been known so far has tended to be speculation. Other works by Jean Blondel include "Voters, Parties and Leaders", "An Introduction to Comparative Government", "Comparative Legislatures", "Political Parties", "The Discipline of Politics", "World Leaders", "The Organisation of Governments", "Government Ministers in the Contemporary World", "Political Leadership" and "Cabinets in Western Europe". Ferdinand Mueller-Rommel is the author of "New Politics in Western Europe", "Cabinets in Western Europe" and "Gruene Parteien in Westeuropa".