Friedman’s theory asserted that inflation would automatically accelerate without limit once unemployment fell below a minimum safe level, which he described as the “natural” unemployment rate. In Friedman’s original work, the natural unemployment rate was a purely theoretical conjecture, founded on an assumption described as “rational expectations,” even though it ran counter to any normal definition of rational behavior.
弗里德曼的理论断言，一旦失业率低于最低安全水平（即他形容的“自然”失业率），通胀便会自动无上限加速攀升。在弗里德曼的原文中，自然失业率是一个纯理论推测，建基于称之为“理性预期”的假设，尽管它违背了任何理性行为的标准定义。