Principal–agent problemThe principal–agent problem refers to the conflict in interests and priorities that arises when one person or entity (the "agent") takes actions on behalf of another person or entity (the "principal"). The problem worsens when there is a greater discrepancy of interests and information between the principal and agent, as well as when the principal lacks the means to punish the agent. The deviation from the principal's interest by the agent is called "agency costs".
Stackelberg competitionThe Stackelberg leadership model is a strategic game in economics in which the leader firm moves first and then the follower firms move sequentially (hence, it is sometimes described as the "leader-follower game"). It is named after the German economist Heinrich Freiherr von Stackelberg who published Marktform und Gleichgewicht [Market Structure and Equilibrium] in 1934, which described the model. In game theory terms, the players of this game are a leader and a follower and they compete on quantity.
Regulated marketA regulated market (RM) or coordinated market is an idealized system where the government or other organizations oversee the market, control the forces of supply and demand, and to some extent regulate the market actions. This can include tasks such as determining who is allowed to enter the market and/or what prices may be charged. The majority of financial markets such as stock exchanges are regulated, whereas over-the-counter markets are usually not at all or only moderately regulated.
Market townA market town is a settlement most common in Europe that obtained by custom or royal charter, in the Middle Ages, a market right, which allowed it to host a regular market; this distinguished it from a village or city. In Britain, small rural towns with a hinterland of villages are still commonly called market towns, as sometimes reflected in their names (e.g. Downham Market, Market Rasen, or Market Drayton). Modern markets are often in special halls, but this is a recent development, and the rise of permanent retail establishments has reduced the need for periodic markets.
