To state that a restraint on trade must be reasonable in the interests both of the parties to the restriction and of the public is to provide an unhelpful, albeit accurate, summary of the common law doctrine. Heydon’s The Restraint of Trade Doctrine, published in 1971, usefully disaggregated the doctrine and Trebilcock treads a similar path in examining the Commonwealth cases concerning restrictive covenants in employment contracts and contracts for the sale of a business, exclusive service contracts and, to a lesser extent, the common law of cartels. Practical problems rarely trouble one area of law alone, and it would be unusual to look only at the restraint of trade doctrine without also considering other areas of the law such as the law of competition, the economic torts or the common law of breach of confidence.

Why then does Trebilcock restrict himself to the common law cases on restraint of trade, thereby eschewing a more problem-oriented approach? The doctrine is at least five centuries old and throughout its history the cases have explicitly acknowledged the influence of economic objectives. Trebilcock has, therefore, taken the opportunity to use this rich source of material in examining the proposition espoused by a number of American academics that the common law exhibits a tendency to the development of economically efficient rules. His analysis of the various strands of the doctrine reveals a number of its features which give lie to any coherent economic theory behind the judicial determination of whether a restraint is or is not justifiable.

In testing a proposition that many practising lawyers will regard as self-evidently wrong and others as irrelevant, Trebilcock nonetheless provides a comprehensible and often effective criticism of such cherished cases as Schroeder Music Publishing Co. Ltd. v. Macaulay [1974] 1 W.L.R. 1308 and Esso Petroleum Ltd. v. Harper’s Garage (Stourport) Ltd. [1968] A.C. 269, while providing food for thought (in the form of commonsense economics) for those who must advise whether a restraint is likely to be held reasonable. The discussion of the historical evolution of the doctrine is probably too brief to be of any lasting value, and Trebilcock’s exclusive focus on restraint of trade cases leaves largely unexplained any similarities with parallel developments in the economic torts. The text occasionally and annoyingly omits the Law Reports citation for cases, although the table of cases does provide a selection of citations. The economic analysis is blissfully free of mathematics and the book contains one solitary graph. Although the work is more in the nature of a law review article than a textbook, it has the advantage of youth over Heydon’s book and it is very reasonably priced.