A monopsony is a market with a single buyer and many sellers.
The buyer has purchasing power because sellers cannot easily find an alternative customer. In labor economics, a monopsony may describe one dominant employer in a local labor market. The employer can influence wages and employment rather than accepting a wage determined entirely by competition among buyers.
Monopsony is the buyer-side counterpart to monopoly, in which a single seller faces many buyers. An oligopsony has a small number of powerful buyers, while a bilateral monopoly has one major buyer and one major seller. These labels describe market structure, not necessarily whether the goods are legal or government-controlled.
Real markets can approximate monopsony without having literally one buyer. Switching costs, geographic isolation, specialized skills, exclusive contracts, or concentrated procurement can limit sellers’ alternatives. Antitrust authorities and labor economists therefore examine buyer concentration and workers’ ability to move, not just the number of firms visible in an industry.