economists define as a market structure with a few large firms
Market structure 2. Oligopoly, in which a market is run by a small number of firms that together control the majority of the market share.
Market economy Market economies range from minimally regulated “free market” and laissez-faire systems - where state activity is restricted to providing public goods and services and safeguarding private ownership[3] - to interventionist forms where the government plays an active role in correcting market failures and promoting social welfare. State-directed or dirigist economies are those where the state plays a directive role in guiding the overall development of the market through industrial policies or indicative planning — which guides but does not substitute the market for economic planning — a form sometimes referred to as a mixed economy.[4][5][6]