Lausanne School

The Lausanne School, also called the Mathematical School, is the neoclassical school of thought built around Leon Walras and Vilfredo Pareto, both professors of political economy at the University of Lausanne in Switzerland. Its central achievement was general equilibrium theory: rather than analyzing one market in isolation, the school modeled how every market in an economy, for every good, every input, every price, is interconnected and reaches a mutually consistent equilibrium simultaneously, mathematician Hermann Laurent later naming the approach after the school in his own writing on mathematical political economy. Walras built the founding mathematical system in the 1870s; Pareto, his successor at Lausanne, refined it and introduced Pareto efficiency, a state where no one can be made better off without making someone else worse off, still the basic welfare-economics benchmark used today. The school's systemic, all-markets-at-once method distinguished it from Alfred Marshall's partial-equilibrium approach, which analyzed one market's supply and demand holding the rest of the economy fixed, and its mathematical general equilibrium framework became foundational to the mainstream neoclassical tradition that followed.