He was the Secretary of the Treasury during the 1920s and under Harding that had the theory that high taxes forced the rich to invest in tax-exempt securities rather than in factories that provided prosperous payrolls. He had followers in his theory called Mellonites. He helped engineer a series of tax reductions and reduced national debt by $10 billion. He was accused of indirectly encouraging the bull market and starting the descent into the stock market crash. Some people, however, believed he was the "greatest secretary of treasury since Hamilton." He used "trickle-down" economics.