Demand

In economics, demand is the utility for a good or service of an economic agent, relative to his/her income. (Note: This distinguishes "demand" from "quantity demanded", where demand is a listing or graphing of quantity demanded at each possible price. In contrast to demand, quantity demanded is the exact quantity demanded at a certain price. Changing the actual price will change the quantity demanded, but it will not change the demand, because demand is a listing of quantities that would be bought at various prices, not just the actual price.)

Demand is a buyer's willingness and ability to pay a price for a specific quantity of a good or service. Demand refers to how much (quantity) of a product or service is desired by buyers at various prices. The quantity demanded is the amount of a product people are willing or able to buy at a certain price; the relationship between price and quantity demanded is known as the demand. (see also supply and demand). The term demand signifies the ability or the willingness to buy a particular commodity at a given point of time, ceteris paribus. Utility preferences and choices underlying demand can be represented as functions of cost, benefit, odds and other variables.

Investment

Investment is time, energy, or matter spent in the hope of future benefits actualized within a specified date or time frame. This article concerns investment in finance.

In finance, investment is buying or creating an asset with the expectation of capital appreciation, dividends (profit), interest earnings, rents, or some combination of these returns. This may or may not be backed by research and analysis. Most or all forms of investment involve some form of risk, such as investment in equities, property, and even fixed interest securities which are subject, among other things, to inflation risk. It is indispensable for project investors to identify and manage the risks related to the investment. Investment and investing is distinguished from other uses of money (such as saving, speculation, donation, gifting), in that the deployment of money is done for the purposes of obtaining a positive expected return.

Overview

In finance, investment is the purchase of an asset or item with the hope that it will generate income or appreciate in the future and be sold at the higher price. It generally does not include deposits with a bank or similar institution. The term investment is usually used when referring to a long-term outlook. This is the opposite of trading or speculation, which are short-term practices involving a much higher degree of risk. Financial assets take many forms and can range from the ultra safe low return government bonds to much higher risk higher reward international stocks. A good investment strategy will diversify the portfolio according to the specified needs.

Aggregate demand

In macroeconomics, aggregate demand (AD) or domestic final demand (DFD) is the total demand for final goods and services in an economy at a given time. It specifies the amounts of goods and services that will be purchased at all possible price levels. This is the demand for the gross domestic product of a country. It is often called effective demand, though at other times this term is distinguished.

The aggregate demand curve is plotted with real output on the horizontal axis and the price level on the vertical axis. It is downward sloping as a result of three distinct effects: Pigou's wealth effect, Keynes' interest rate effect and the Mundell-Fleming exchange-rate effect. The Pigou effect states that a higher price level implies lower real wealth and therefore lower consumption spending, giving a lower quantity of goods demanded in the aggregate. The Keynes effect states that a higher price level implies a lower real money supply and therefore higher interest rates resulting from financial market equilibrium, in turn resulting in lower investment spending on new physical capital and hence a lower quantity of goods being demanded in the aggregate.

Demand curve

In economics, the demand curve is the graph depicting the relationship between the price of a certain commodity and the amount of it that consumers are willing and able to purchase at that given price. It is a graphic representation of a demand schedule. The demand curve for all consumers together follows from the demand curve of every individual consumer: the individual demands at each price are added together.

Demand curves are used to estimate behaviors in competitive markets, and are often combined with supply curves to estimate the equilibrium price (the price at which sellers together are willing to sell the same amount as buyers together are willing to buy, also known as market clearing price) and the equilibrium quantity (the amount of that good or service that will be produced and bought without surplus/excess supply or shortage/excess demand) of that market. In a monopolistic market, the demand curve facing the monopolist is simply the market demand curve.

Characteristics

Supply and demand

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, or other traded item such as labor or liquid financial assets, will vary until it settles at a point where the quantity demanded (at the current price) will equal the quantity supplied (at the current price), resulting in an economic equilibrium for price and quantity transacted.

Graphical representation of supply and demand

Although it is normal to regard the quantity demanded and the quantity supplied as functions of the price of the goods, the standard graphical representation, usually attributed to Alfred Marshall, has price on the vertical axis and quantity on the horizontal axis, the opposite of the standard convention for the representation of a mathematical function.

Since determinants of supply and demand other than the price of the goods in question are not explicitly represented in the supply-demand diagram, changes in the values of these variables are represented by moving the supply and demand curves (often described as "shifts" in the curves). By contrast, responses to changes in the price of the good are represented as movements along unchanged supply and demand curves.