growth, measured as real output per hour of all persons, increased at an average rate of 1.9% during Reagan's eight years, compared to an average 1.3% during the preceding eight years. Federal net outlays as a percent of GDP averaged 21.4% under Reagan, compared to 19.1% during the preceding eight years. During the Nixon and Ford Administrations, before Reagan's election, a combined supply and demand side policy was considered unconventional by the moderate wing of the Republican Party. While running against Reagan for the Presidential nomination in 1980, George H. W. Bush had derided Reaganomics as "voodoo economics". Similarly, in 1976, Gerald Ford had severely criticized Reagan's proposal to turn back a large part of the Federal budget to the states. Justifications In his 1980 campaign speeches, Reagan presented his economic proposals as a return to the free enterprise principles, free market economy that had been in favor before the Great Depression and FDR's New Deal policies. At the same time he attracted a following from the supply-side economics movement, which formed in opposition to Keynesian demand-stimulus economics. This movement produced some of the strongest supporters for Reagan's policies during his term in office. The contention of the proponents, that the tax rate cuts would more than cover any increases in federal debt, was influenced by a theoretical taxation model based on the elasticity of tax rates, known as the Laffer curve. Arthur Laffer's model predicts that excessive tax rates actually reduce potential tax revenues, by lowering the incentive to produce; the model also predicts that insufficient tax rates (rates below the optimum level for a given economy) lead directly to a reduction in tax revenues. Ronald Reagan also cited the 14th-century Arab scholar Ibn Khaldun as an influence on his supply-side economic policies, in 1981. Reagan paraphrased Ibn Khaldun, who said that "In the beginning of the dynasty, great tax revenues were gained from small assessments," and that "at the end of the dynasty, small tax revenues were gained from large assessments." Reagan said his goal is "trying to get down to the small assessments and the great revenues." Policies Reagan lifted remaining domestic petroleum price and allocation controls on January 28, 1981, and lowered the oil windfall profits tax in August 1981. He ended the oil windfall profits tax in 1988. During the first year of Reagan's presidency, federal income tax rates were lowered significantly with the signing