- 
Aggregate DemandThe combined demand of all buyers in a market. 
- 
Aggregate SupplyThe combined supply of all sellers in a market. 
- 
BuyerSomeone who purchases goods and services from a seller for money. 
- 
Complementary GoodA good is called a complementary good if the demand for the good increases with demand for another good. One extreme example: right shoes are complementary goods for left shoes. 
- 
DemandDemand refers to the amount of goods and services that buyers are willing to purchase. Typically, demand decreases with increases in price, this trend can be graphically represented with a demand curve. Demand can be affected by changes in income, changes in price, and changes in relative price. 
- 
Demand CurveA demand curve is the graphical representation of the relationship between quantities of goods and services that buyers are willing to purchase and the price of those goods and services. 
- 
Equilibrium PriceThe price of a good or service at which quantity supplied is equal to quantity demanded. Also called the market-clearing price. 
- 
Equilibrium QuantityAmount of goods or services sold at the equilibrium price. Because supply is equal to demand at this point, there is no surplus or shortage. 
- 
FirmUnit of sellers in microeconomics. Because it is seen as one selling unit in microeconomics, a firm will make coordinated efforts to maximize its profit through sales of its goods and services. The combined actions and preferences of all firms in a market will determine the appearance and behavior of the supply curve. 
- 
Goods and ServicesProducts or work that can be bought and sold. In a market economy, competition among buyers and sellers sets the market equilibrium, determining the price and the quantity sold. 
- 
Horizontal additionThe process of adding together all quantities demanded at each price level to find aggregate supply or aggregate demand. 
- 
HouseholdUnit of buyers in microeconomics. Because it is seen as one buying unit in microeconomics, a household will make coordinated efforts to maximize its utility through its choices of goods and services. The combined actions and preferences of all households in a market will determine the appearance and behavior of the demand curve. 
- 
Labor marketA large group of firms and workers in the same industry: the firms want to hire workers, the workers want jobs. The interaction between the two groups determines the market wage and quantity of labor used. 
- 
Law of Diminishing ReturnsConcept that the marginal revenue derived from additional units of labor decreases as quantities of labor increases. 
- 
Marginal ProductThe additional amount of goods generated by using one more unit of work. 
- 
Marginal Revenue ProductThe additional income generated by using one more unit of input. 
- 
Marginal Revenue Product of LaborThe additional income generated by using one more unit of work. 
- 
MarketA large group of buyers and sellers who are buying and selling the same good or service. 
- 
Market-clearing PriceThe price of a good or service at which quantity supplied is equal to quantity demanded. Also called the equilibrium price. 
- 
OptimizationTo maximize utility by making the most effective use of available resources, whether they be money, goods, or other factors. 
- 
Price CeilingMaximum price set by the government on a specific good. Usually is set below market price, causing a shortage. 
- 
Price FloorMinimum price set by the government on a specific good. Usually is set above market price, causing a surplus. 
- 
RevenueThe income a firm makes from selling its products. Revenue as equal to price per unit times quantity sold, (P)x(Q). 
- 
SellerSomeone who sells goods and services to a buyer for money. 
- 
SupplySupply refers to the amount of goods and services that sellers are willing to sell. Typically, supply increases with increases in price, this trend can be graphically represented with a supply curve. 
- 
Supply CurveA supply curve is the graphical representation of the relationship between quantities of goods and services that sellers are willing to sell and the price of those goods and services. 
- 
SurplusSituation in which the quantity supplied exceeds the quantity demanded for goods and services or labor; in this situation, the price (or wage) is above the equilibrium price (or wage). 
- 
WagePrice per unit of time when the good being sold is some form of labor or work (instead of a physical product). 
 
         
   
                     
                     
                    