2010 Oxford University study predicted that production would peak before 2015, but its projection of a change soon "... from a demand-led market to a supply constrained market ..." was incorrect. A 2014 validation of a significant 2004 study in the journal Energy proposed that it is likely that conventional oil production peaked, according to various definitions, between 2005 and 2011. A set of models published in a 2014 Ph.D. thesis predicted that a 2012 peak would be followed by a drop in oil prices, which in some scenarios could turn into a rapid rise in prices thereafter. According to energy blogger Ron Patterson, the peak of world oil production was probably around 2010. Major oil companies hit peak production in 2005. Several sources in 2006 and 2007 predicted that worldwide production was at or past its maximum. However, in 2013 OPEC's figures showed that world crude oil production and remaining proven reserves were at record highs. According to Matthew Simmons, former Chairman of Simmons & Company International and author of Twilight in the Desert: The Coming Saudi Oil Shock and the World Economy, "peaking is one of these fuzzy events that you only know clearly when you see it through a rear view mirror, and by then an alternate resolution is generally too late." Possible consequences The wide use of fossil fuels has been one of the most important stimuli of economic growth and prosperity since the industrial revolution, allowing humans to participate in takedown, or the consumption of energy at a greater rate than it is being replaced. Some believe that when oil production decreases, human culture and modern technological society will be forced to change drastically. The impact of peak oil will depend heavily on the rate of decline and the development and adoption of effective alternatives. In 2005, the United States Department of Energy published a report titled Peaking of World Oil Production: Impacts, Mitigation, & Risk Management. Known as the Hirsch report, it stated, "The peaking of world oil production presents the U.S. and the world with an unprecedented risk management problem. As peaking is approached, liquid fuel prices and price volatility will increase dramatically, and, without timely mitigation, the economic, social, and political costs will be unprecedented. Viable mitigation options exist on both the supply and demand sides, but to have substantial impact, they must be initiated more than a decade in advance of