marginalist

A marginalist is someone who adheres to or practices marginalism, an economic theory that emphasizes the importance of marginal utility and marginal costs in determining value and decision-making.

Marginalists focus on the additional benefit or cost of one more unit of something rather than total or average values.

The term appears most often in discussions of economic history and theory, particularly regarding the late 19th-century revolution in economic thought.

The marginalists broke from classical economists by explaining prices through subjective utility rather than labor costs.