In "Man, Economy, and State", Rothbard divides the various kinds of state intervention in three categories: "autistic intervention", which is interference with private non-economic activities; "binary intervention", which is forced exchange between individuals and the state; and "triangular intervention", which is state-mandated exchange between individuals. According to Sanford Ikeda, Rothbard's typology "eliminates the gaps and inconsistencies that appear in Mises's original formulation". Rothbard writes in "Power and Market" that the role of the economist in a free market is limited, but it is much larger in a government that solicits economic policy recommendations. Rothbard argues that self-interest therefore prejudices the views of many economists in favor of increased government intervention.