セイの法則
Jean-Baptiste Say (; 5 January 1767 – 15 November 1832) was a liberal French economist and businessman who argued in favor of competition, free trade and lifting restraints on business. He is best known for Say's law—also known as the law of markets—which he popularized. Scholars disagree on the surprisingly subtle question of whether it was Say who first stated what is now called Say's law. Moreover, he was one of the first economists to study entrepreneurship and conceptualized entrepreneurs as organizers and leaders of the economy.