privatization may vary depending on the privatization model employed. According to Dr Irwin Stelzer, "it is somewhere between difficult and impossible to separate the effects of privatisation from the effects of such things as trends in the economy". According to research performed by the World Bank and William L. Megginson in the early 2000s, privatization in competitive industries with well-informed consumers, consistently improved efficiency. According to APEC, the more competitive the industry, the greater the improvement in output, profitability, and efficiency. Such efficiency gains mean a one-off increase in GDP, but through improved incentives to innovate and reduce costs also tend to raise the rate of economic growth. More recent research and literature review performed by Professor Saul Estrin and Adeline Pelletier concluded that "the literature now reflects a more cautious and nuanced evaluation of privatization" and that "private ownership alone is no longer argued to automatically generate economic gains in developing economies". According to a 2008 study published in Annals of Public and Cooperative Economics, liberalization and privatization has produced mixed results. Although typically there are many costs associated with these efficiency gains, many economists argue that these can be dealt with by appropriate government support through redistribution and perhaps retraining. Yet, some empirical literature suggests that privatization could also have very modest effects on efficiency and quite regressive distributive impact. In the first attempt at a social welfare analysis of the British privatization program under the Conservative governments of Margaret Thatcher and John Major during the 1980s and 1990s, Massimo Florio points to the absence of any productivity shock resulting strictly from ownership change. Instead, the impact on the previously nationalized companies of the UK productivity leap under the Conservatives varied in different industries. In some cases, it occurred prior to privatization, and in other cases, it occurred upon privatization or several years afterward. A 2012 study published by the European Commission argues that privatisation in Europe had mixed effects on service quality and has achieved only minor productivity gains, driven mainly by lower labour input combined with other cost cutting strategies that led to a deterioration of employment and working conditions. Meanwhile, a different study by the Commission found that the UK rail network (which was privatized from 1994 to 1997) was most improved out of all the 27 EU nations from 1997 to 2012. The report examined a range of 14 different factors and the UK