The purpose of this book is to present the findings of a research project and to consider their implications for public policy. The project was designed to find out what effect the 1956 Restrictive Trade Practices Act (and the subsequent legislation of 1968) had on British industry. The project itself had a twofold origin. It was a logical extension of our study of information agreements 1 and embodied techniques developed in that study. But equally important was a feeling of some dissatisfaction with the way in which studies of restrictive practices policy in the United Kingdom had developed. To a considerable degree economists had been involved in what may be termed ‘case-mongering’. That is to say both books and articles had concerned themselves with two main topics: (a) the evolution and present nature of the law and (b) the Judgements of the Court. Judgements had been mulled over, errors of economic logic had been exposed and inconsistencies between one finding and another had been highlighted. (A similar approach had often been evident in the case of monopolies and mergers.) It was no part of our argument that this kind of activity was without value. Clearly it was important that scholars should be concerned with assessing how well-conceived legislation was and in this respect the economist had much to offer. Equally the industrial economist in particular was concerned with the way in which the Court had approached individual cases. We should further point out that we could hardly object to this kind of activity in view of the fact that in our separately published case studies we have indulged in it ourselves. What did, however, disturb the authors was the incompleteness of much of this activity. Incompleteness in this context refers to the failure to follow out the effects of Judgements. Clearly this is crucial to any assessment of policy. In case this charge of neglect appears to be all-inclusive we would readily admit that there have been honourable exceptions – the most notable being J. B. Heath whose early investigation, the results of which were published in the Manchester School, 2 must be regarded as a pioneering piece of work within the U.K. context. Another most important exception is those economists who have been directly associated with the work of the Monopolies Commission and the Restrictive Practices Court. Clearly they have been involved in the anti-trust field in the most practical way and 14the results, even if sometimes unadvertised, have been extremely important.