Basic market structures: competitive market, monopolistic competition, oligopoly, monopoly. Levels of concentration and its consequences. Behaviour of market actors. Elements of market structure. Transaction costs and the theory of the firm. Information: perfect information vs. information asymmetries. Moral hazard, free-riding, rent-seeking. The principal – agent model. The structure – conduct – performance approach. The role of the state in a market economy. Antitrust regulation. Economics of regulation. State capture.