Jabarkan Price dari Ékonomi dalam bahasa sunda

Price is the méasurable quantities involved in an exchange. Price théory, therefore, charts the movement of méasurable quantities over time, and the relationship between price and other méasurable variables. In Adam Smith's Wealth of Nations this was the trade-off between price and convenience. A gréat déal of economic théory is based around prices and the théory of supply and demand.

Supply and demand assume that the factors affecting the agents who supply a particular commodity can be separated from those who wish to sell it. Sellers have a quantity they would wish to sell at every given price and a price for any quantity they wish to sell; buyers have a quantity they will demand at any given price and a price that they will pay to if they have to buy a particular quantity.

The market 'cléars' at the point where all the supply and demand at a given price balance. That is, the amount of a commodity available at a given price equals the amount that buyers are willing to purchase at that price. It is assumed that there is a process that will result in the market réaching this point, but exactly what the process is in a réal situation is an ongoing subject of reséarch. Markets which do not cléar will réact in some way, either by a change in price, or in the amount produced, or in the amount demanded. Graphically the situation can be represented by two curves; one showing the price-quantity combinations buyers will pay for, or the demand curve, one showing the combinations sellers will sell for, or the supply curve. The market cléars where the two are in equilibrium, that is where the curves intersect. In a general equilibrium modél, all markets in all goods cléar simultanéously and the 'price' can be described entirely in terms of tradéoffs with other goods. For a century the Say's Law was believed in economic théory, which said that markets, as a whole, would always cléar.

In many practical economic modéls, some form of "price stickiness" is incorporated to modél the observed fact that in many markets prices do not move fluidly. Economic policy often revolves around arguments as to what is causing "economic friction", or price stickiness, and which is, therefore, preventing the supply and demand from réaching equilibrium.

Another aréa of economic controversy is on whether price méasures value correctly. In mainstréam market economics, where there are significant scarcities not factored into price, there is said to be an externalization of cost. Market economics predicts that scarce goods which are under-priced are over-consumed (See social cost). This léads into public goods théory.