In microeconomics, supply and demand is an economic model of price determination in a market. It concludes that in a competitive market, the unit price for a particular good will vary until it settles at a point where the quantity demanded by consumers (at current price) will equal the quantity supplied by producers (at current price), resulting in an economic equilibrium for price and quantity.
The four basic laws of supply and demand are::37
A free price system or free price mechanism (informally called the price system or the price mechanism) is an economic system where prices are set by the interchange of supply and demand, with the resulting prices being understood as signals that are communicated between producers and consumers which serve to guide the production and distribution of resources. Through the free price system, supplies are rationed, income is distributed, and resources are allocated. A free price system contrasts with a controlled or fixed price system where prices are set by government, within a controlled market or planned economy.
Rather than prices being set by the state, as in a command economy with a fixed price system, prices are determined in a decentralized fashion by trades that occur as a result of sellers' asking prices matching buyers' bid prices as a result of subjective value judgement in a market economy. Since resources of consumers are limited at any given time, consumers are relegated to satisfying wants in a descending hierarchy and bidding prices relative to the urgency of a variety of wants. This information on relative values is communicated, through price signals, to producers whose resources are also limited. In turn, relative prices for the productive services are established. The interchange of these two sets of prices establish market value, and serve to guide the rationing of resources, distributing income, and allocating resources.