Media enterprises are under more severe pressure today than perhaps at any time in their history. National newspapers throughout the western world are shedding jobs, regional newspapers are closing, broadcasters are reining in expenditure and closing foreign bureaux. Two factors have conspired to challenge the traditional business model of media corporations. \n\nFirst, the cyclical problem of a global economic recession is being compounded by the progressive migration of advertising revenue to the web. Second, new technologies are fragmenting audiences and transforming consumer behaviour. With newspaper readership and TV news in decline, both the print and broadcast media are finding it increasingly difficult to make journalism profitable. Attempts to monetise the web show no prospect of compensating for lost revenue. \n\nFor many of these companies, the easiest route to survival is some form of amalgamation with other media enterprises. There is an industrial logic to such consolidation which allows for rationalisation of 'back office' functions, greater centralisation and - theoretically - release of resources to invest in the core activity of news production. \n\nBut what of the impact on media pluralism? Diversity of expression and editorial approach underpins democratic life: the fewer media outlets which control those editorial agendas, the less healthy it is for a vibrant democracy. There is some compensation from the cacophany of voices on the internet, but these are fragmented and often unreliable sources with tiny audiences which conduct virtually no newsgathering. For the vast majority of people in mature democracies, the traditional press and broadcasting instutions are still by far the most important conduits for information and debates about the world around them.\n\nThis raises two crucial issues. First, in what ways does the ownership of a media enterprise actually impact on editorial output? Theoretical concerns about the dangers of consolidation require some empirical evidence of how influence is exerted on editorial direction, distribution of journalistic resources, investment in foreign reporting and overseas bureaux, deployment of specialist correspondents, the omission and commission of particular stories, and the myriad ways in which news organisations organise their journalistic priorities. In broadcasting, which in Western Europe is governed by impartiality requirements, slightly different questions are raised about whether and how these requirements impact on editorial diversity. A comparison of experience in the UK and the US where the equivalent 'Fairness Doctrine' was abolished 25 years ago would be instructive.\n\nSecond, what policy initiatives might reconcile the apparently conflicting aims of media pluralism and industry consolidation? For struggling media corporations, consolidation is a blunt but usually effective form of salvation. For governments, a policy regime which prevents consolidation can be equally blunt as well as politically difficult in the face of threatened job losses and bankruptcies. Creative solutions such as Trusts, incentives for smaller media businesses, guarantees of investment in journalism, or other structural means (including public funding) of mitigating the effects of concentrated media power urgently need to be explored.\n\nDuring the course of 2007/8, I was special adviser to a House of Lords select committee which examined and reported on News and Media Ownership. The enquiry, which included a visit to the US, compiled a huge volume of oral and written evidence on the editorial influence of owners and on the policy regime governing media ownership. Using that material - which has never been properly exploited - and supplementing it with original interviews with UK policy makers and regulators, this study will seek to address the question of whether and how media diversity can be sustained in the face of unparalled economic and technological upheaval.