1900-1911: A Dualistic Methodology and Choice Theory
By 1900 Pareto’s methodology had evolved into an essentially dualistic, but still positive, approach. The genesis of this change in Pareto’s methodology was his shift toward a political sociology and the development of the distinction between logical and non-logical action.
As a result of this distinction, the Walrasian core of Pareto’s theory diminished with the recognition that consistency of choice in unchanged circumstances is an important aspect of logical action, culminating in the emergence of choice theory based on preference ordering. As in the previous section, the discussion of the main themes will generally commence with reference to Pareto’s early economic articles and conclude with reference to his contribution to that theme in his books, which during this phase were the Italian and French editions of the Manual of Political Economy. The work from this phases was crowned by Pareto’s “Economie mathematique” (1911), which was published in Encyclopedie des Sciences Mathematiques Pures et Appliques. The main themes covered over this period concern methodology, pure economic theory, and welfare economics.