This book collects some of the author's most illuminating recent papers on competition policy published since the turn of the millennium. They focus on three main themes: how technological innovation leads to monopolistic market structures and is reciprocally influenced by them; how competition agencies deal with the links from merger to economic efficiency, static and dynamic; and the behavioral problems posed by 'tacit' collusion and monopoly power in vertical market chains. Taken together they provide unique insight into competition, mergers and monopolies from one of the leading pioneers in the field.