Monday, June 11, 2007

Core economic concepts

Value

The concept of value is central to economics. An observable measure of it is market price.

Representative money like this 1922 US $100 gold note could be exchanged by the bearer for its face value in gold.
Representative money like this 1922 US $100 gold note could be exchanged by the bearer for its face value in gold.

Adam Smith defined labor as the underlying source of value,[10] and the "labor theory of value" underlies the work of Karl Marx, David Ricardo and many other classical economists. This theory argues that a good or service is worth the labor that it takes to produce. For most, this value determines a commodity's price. This labor theory of price and the closely related cost-of-production theory of value dominates the work of most classical economists, but those theories are far from the only accepted basis for "value". For example, Austrian School economists use the marginal theory of value.

Neoclassical economics, as in John R. Hicks's book Value and Capital, distinguishes value (as determined on the demand side) from cost (on the supply side), with price determined by supply and demand.[16] In a competitive market, supply and demand interact to determine price and equate cost and value. Economic analysis considers not only the allocation of output for different uses but the distribution of income to the factors of production, including labour and capital, through factor markets.

[edit] Supply and demand

The supply and demand model describes how prices vary as a result of a balance between product availability and demand. The graph depicts a right-shift in demand from D1 to D2 along with the consequent increase in price and quantity required to reach a new equilibrium point on the supply curve (S).
The supply and demand model describes how prices vary as a result of a balance between product availability and demand. The graph depicts a right-shift in demand from D1 to D2 along with the consequent increase in price and quantity required to reach a new equilibrium point on the supply curve (S).
Main article: Supply and demand

In microeconomic theory supply and demand attempts to describe, explain, and predict the price and quantity of goods sold in perfectly competitive markets. It is one of the most fundamental economic models, ubiquitously used as a basic building block in a wide range of more detailed economic models and theories.

To define, demand is the quantity of a product that a consumer or buyer would be willing and able to buy at any given price in a given period of time. Demand is often represented as a table or a graph relating price and quantity demanded. Most economic models assume that consumers make rational choices about how much to buy in order to maximize their utility - they spend their income on the products that will give them the most happiness at the least cost. The law of demand states that, in general, price and quantity demanded are inversely related. In other words, the higher the price of a product, the less of it consumers will buy.

Supply is the quantity of goods that a producer or a supplier is willing to bring into the market for the purpose of sale at any given price in a given period of time. Supply is often represented as a table or a graph relating price and quantity supplied. Like consumers, producers are assumed to be utility-maximizing, attempting to produce the amount of goods that will bring them the greatest possible profit. The law of supply states that price and quantity supplied are directly proportional. In other words, the higher the price of a product, the more of it producers will create.

The theory of supply and demand is crucial to explaining the market economy in that it explains the mechanisms by which prices and levels of production are set.

[edit] Price

Main article: Price

In order to measure the ebb and flow of supply and demand, a measurable value is needed. The oldest and most commonly used is price, or the going rate of exchange between buyers and sellers in a market. Price theory, therefore, charts the movement of measurable quantities over time, and the relationship between price and other measurable variables. In Adam Smith's Wealth of Nations, this was the trade-off between price and convenience.[10] A great deal of economic theory is based around prices and the theory of supply and demand. In economic theory, the most efficient form of communication comes about when changes to an economy occur through price, such as when an increase in supply leads to a lower price, or an increase in demand leads to a higher price.

Exchange rates are determined by the relative supply and demand of different currencies — an important issue in international trade.
Exchange rates are determined by the relative supply and demand of different currencies — an important issue in international trade.

In many practical economic models, some form of "price stickiness" is incorporated to model the fact that prices do not move fluidly in many markets. Economic policy often revolves around arguments about the cause of "economic friction", or price stickiness, and which is, therefore, preventing the supply and demand from reaching equilibrium.

Another area of economic controversy is about whether price measures the value of a good correctly. In mainstream market economics, where there are significant scarcities not factored into price, there is said to be an externalization, which is a cost or benefit to actors other than the buyer and seller, of which many examples exist, including pollution (a cost to others) and education (a benefit to others). Market economics predicts that scarce goods which are under-priced because of externalities are over-consumed (See social cost), and that scarce goods that are over-priced are under-consumed. This leads into public goods theory. Governments often tax and otherwise restrict the sale of goods that have negative externalities and subsidize or otherwise promote the purchase of goods that have positive externalities in an effort to correct the distortion in price caused by these externalities.

[edit] Scarcity

Main article: Scarcity

Neoclassical economics is characterized by maximization (leisure time, wealth, health, and other sources of happiness - all commonly reduced to the concept of utility) subject to constraints. These constraints - or scarcity - inevitably define a trade-off. For example, one can have more money by working harder, but less time (there are only so many hours in a day, so time is scarce). One can have more radishes only at the expense of, for example, fewer carrots (you only have so much land on which to grow food - land is scarce).

All economies in the world face scarcity

Scarcity is defined as: when the price is zero, the quantity demanded exceeds the quantity supplied. Price is a measure of relative scarcity. If all other market variables are held constant. When the price is rising, this indicates the commodity is becoming relatively scarcer. When the price is falling, this indicates the commodity is becoming relatively less scarce.

Adam Smith considered, for example, the trade-off between time, or convenience, and money. He discussed how a person could live near town, and pay more for rent of his home, or live farther away and pay less, "paying the difference out of his convenience".[10]

[edit] Marginalism

Main article: Marginalism

In marginalist economic theory, the price level is determined by the marginal cost and marginal utility. The price of all goods will be the cost of making the last one that people will purchase, and the price of all the employees in a company will be the cost of hiring the last one the business needs. Marginalism looks at decisions based on "the margins", what the cost to produce the next unit is, versus how much it is expected to return in profit. When the marginal return of an action reaches zero, the action stops. Marginal utility is how much more happiness or use a person receives from a purchase in contrast with buying less. Marginal rewards are often subject to diminishing returns: Less reward is obtained from more production or consumption. For example, the 10th bar of chocolate that a person consumes does not taste as good as the first, and so brings less marginal utility.

Marginalism became increasingly important in economic theory in the late 19th century, and is a tool which is used to analyze how economic systems will react. Marginal cost of production divides costs into "fixed" costs which must be paid regardless of how many of a commodity are produced, and "variable costs". The marginal cost is the variable cost of the last unit. Marginalism states that when the profit from the next unit will be zero, that unit will not be produced. This is often termed the marginal revolution in economic thought.

The marginalist theory of price level runs counter to the classical theory of price being determined by the amount of labor congealed in a commodity.

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