2006 the government published the Air Transport White Paper Progress Report 2006 to report on progress made in "… delivering a sustainable future for aviation." The report re-iterates the government's commitment to the strategy defined in the original White Paper, stating that it "… strikes the right balance between economic, social and environmental goals." It also reports that; the extra runway at Edinburgh airport is now thought unlikely to be needed before 2020; Bristol airport does not currently see a case to support extending its runway, although the option will be kept under review; the additional runway at Stansted airport is not expected to be operational before 2015; and the runway extension at Liverpool airport is now being proposed for early next decade. Elsewhere, recent forecasts conducted for Birmingham airport indicate that a new runway will not be required there before 2030. Following the publication of the White Paper, the Project for the Sustainable Development of Heathrow ('Project Heathrow' for short) was set up to examine how expansion at Heathrow could best be accomplished within the constraints of the stringent environmental limits the White Paper required. A provisional assessment indicates that increased usage of the existing runways could be realised without increasing the number of people affected by noise if 'mixed mode' operations (the simultaneous use of both runways for arrivals and departures) are phased in gradually as noisier aircraft are retired. Indications ahead of the Project Heathrow environmental assessment indicate that increased noise and deterioration in air quality are likely to significantly constrain traffic using a new third runway. These issues are to be addressed as part of a three-month consultation beginning in December 2007, and considerable opposition is being mobilised against the expansion of Heathrow. Economic contribution The aviation industry and the government have together commissioned two significant studies into the economic contribution of air transport, both undertaken by the consultancy Oxford Economic Forecasting (OEF). The first; The Contribution of the Aviation Industry to the UK Economy, was published in 1999 and was used as a source of economic information in The Future of Air Transport White Paper. The second study; The Economic Contribution of the Aviation Industry in the UK, co-sponsored by the national tourist agency VisitBritain, was published in October 2006 to extend and update the earlier report, and was used as a source in the Air Transport White Paper Progress Report 2006. Both studies concluded