of this book by remarking upon how much has changed since the previous edition. For this edition there is a signifi cant change of a diff erent kind, which is the addition of David Bailey as a co-author of the book. David worked as a research assistant on the fi ft h edition, contributed signifi cantly to the sixth, and now shares responsibility, and credit(!), for the seventh. Richard is delighted that David has become party to what is now a joint venture. Of course, it is also true to say that there has been an enormous amount of change to the law, even in the three years between the last edition and this one. Th e most important development, though not involving any change of the law as such, is probably the publication of the Guidance on the Commission’s enforcement priorities in applying Article [102 TFEU] to abusive exclusionary conduct by dominant undertakings. Th e preface to the sixth edition predicted that the Commission would not publish guidelines setting out the law: that proved to be a correct prediction. It speculated that instead the Commission might make a statement as to the ‘principles’ it would apply when deciding which types of abuse, or which economic sectors, to investigate: that was almost correct, except that the document in question explains the Commission’s ‘enforcement priorities’, not quite the same as ‘principles’. Th e publication of these Enforcement priorities has provoked a huge amount of debate, not always supportive of the Commission’s approach. We are supportive. Th e Enforcement priorities do not state the law: it is for the EU Courts to decide what the law is. But they do shed light on what a ‘more economic approach’ to the application of Article 102 TFEU might look like in practice, and it is not unreasonable to suppose that they will have a subtle infl uence on the future orientation of the law. Th is is all work-in-progress: it will be for the ninth edition of this book (probably not the eighth) to refl ect on what infl uence the Enforcement priorities will have had in practice. We have tried very hard to weave the Enforcement priorities into the text, but without in any sense treating them as a statement of the law: we repeatedly tell our students at King’s not to fall into error by treating the Enforcement priorities as guidelines setting out the law; the two should not be elided.