To characterize the kind of state Putin had built in socio-economic terms, in early 2008 professor Marshall I. Goldman coined the term "petrostate" in "Petrostate: Putin, Power, and the New Russia", where he "inter alia" argued that while Putin had followed the advice of economic advisers in implementing reforms such as a 13 percent flat tax and creating a stabilization fund to lessen inflationary pressure, his main personal contribution was the idea of creating "national champions" and the renationalization of major energy assets. In his June 2008 interview, Marshall Goldman said that in his opinion Putin had created a new class of oligarchs, whom some called "silogarchs", Russia having come in second in the "Forbes" magazine list of the world's billionaires after only the United States.