economics

Frieda is at her local florist to buy a dozen roses. She is willing to pay $75 for the roses, and buys them for $75. Frieda's consumer surplus from the purchase is $150. $75. $37.50. $0.

$0.

Which of the following is evidence of a surplus of bananas? A) Firms raise the price of bananas.B) The price of bananas is lowered in order to increase sales. C) The equilibrium price of bananas rises due to an increase in demand. D) The quantity of bananas demanded is greater than the quantity supplied.

.B) The price of bananas is lowered in order to increase sales.

Suppose the U.S. government encouraged consumers to trade in their old automobiles for more efficient, new models by paying up to $5,000 for the old automobiles. These consumers who did trade in their old automobiles to take advantage of the government offer would be exemplifying the economic idea thatA) people are rational.B) people respond to economic incentives.C) optimal decisions are made at the margin.D) equity is more important than efficiency.

.B) people respond to economic incentives

Pierre can produce either a combination of 20 bow ties and 30 neckties or a combination of 35 bow ties and 15 neckties. If he now produces 35 bow ties and 15 neckties, what is the opportunity cost of producing an additional 15 neckties?A) 2 bow tiesB) 15 bow tiesC) 20 bow ties

15 bow ties

The Coffee Nook, a small cafe near campus, sells cappuccinos for $2.50 and Russian tea cakes for $1.00 each. What is the opportunity cost of buying a cappuccino? 2 1/2 Russian tea cakes 2/5 of a Russian tea cake $2.50 $1.00

2.5 Russian Tea cakes

Arthur buys a new cell phone for $150. He receives consumer surplus of $150 from the purchase. What value does Arthur place on his cell phone?A) $0B) $150C) $225D) $300

300

Which of the following statements is true?A) An increase in supply causes a change in equilibrium price; the change in price does not cause a further change in demand or supply.B) A decrease in supply causes equilibrium price to rise; the increase in price then results in a decrease in demand. C) If both demand and supply increase there must be an increase in equilibrium price; equilibrium quantity may either increase or decrease. D) If demand decreases and supply increases one cannot determine if equilibrium price will increase or decrease without knowing which change is greater.

A) An increase in supply causes a change in equilibrium price; the change in price does not cause a further change in demand or supply.

Which of the following generates productive efficiency?A) competition among sellersB) competition among buyersC) government inspectorsD) government production rules and regulations

A) competition among sellers

If an increase in income leads to a decrease in the demand for popcorn, then popcorn is A. an inferior good. B. a neutral good. C. a necessity. D. a normal good.

A. an inferior good.

When the price of a normal good falls, consumers buy a larger quantity because of the ________ effect and the ________ effect. A. substitution; income B. normal; inferior C. substitute; complement D. supply; demand

A. substitution; income

2) What is the difference between an "increase in demand" and an "increase in quantity demanded"? A. There is no difference between the two terms; they both refer to a shift of the demand curve. B.An "increase in demand" is represented by a rightward shift of the demand curve while an "increase in quantity demanded" is represented by a movement along a given demand curve. C. There is no difference between the two terms; they both refer to a movement downward along a given demand curve. D. An "increase in demand" is represented by a movement along a given demand curve, while an "increase in quantity demanded" is represented by a rightward shift of the demand curve.

An "increase in demand" is represented by a rightward shift of the demand curve while an "increase in quantity demanded" is represented by a movement along a given demand curve.

22) What is the difference between an "increase in demand" and an "increase in quantity demanded"?

An "increase in demand" is represented by a rightward shift of the demand curve while an "increase in quantity demanded" is represented by a movement along a given demand curve.

Which of the following is the correct way to describe equilibrium in a market? At equilibrium, demand equals supply. At equilibrium, quantity demanded equals quantity supplied. At equilibrium, market forces no longer apply. At equilibrium, scarcity is eliminated.

At equilibrium, quantity demanded equals quantity supplied.

Studies have shown that drinking one glass of red wine per day may help prevent heart disease. Assume this is true, and favorable weather has increased the grape harvest of California vineyards. In the market for red wine, these two developments wouldA) increase demand and decrease supply, resulting in an increase in the equilibrium quantity and a decrease in the equilibrium price of red wine. B) increase demand and increase supply, resulting in an increase in the equilibrium quantity and an uncertain effect on the equilibrium price of red wine. C) increase demand and increase supply, resulting in an increase in the equilibrium price and an uncertain effect on the equilibrium quantity of red wine. D) increase demand and increase supply, resulting in an increase in both the equilibrium price and the equilibrium quantity of red wine.

B) increase demand and increase supply, resulting in an increase in the equilibrium quantity and an uncertain effect on the equilibrium price of red wine.

In recent years, the cost of producing organic produce in the United States has decreased largely due technological advancement. At the same time, more and more Americans prefer organic produce over conventional produce. Which of the following best explains the effect of these events in the organic produce market?

Both the supply and demand curves have shifted to the right. As a result, there has been an increase in the equilibrium quantity and an uncertain effect on the equilibrium price.

During the Covid-19 pandemic, most cities implemented bans on indoor dining. What happened in the indoor dining market once this ban was lifted and people were anxious to switch from dining at home to dining in restaurants?A) The quantity demanded decreased.B) The demand curve shifted to the left. C) The demand curve shifted to the right.D) The quantity demanded increased.

C) The demand curve shifted to the right.

If the price of grapefruit rises, the substitution effect due to the price change will cause A. a decrease in the demand for grapefruit. B. a decrease in the demand for oranges, a substitute for grapefruit. C. a decrease in the quantity of grapefruit demanded. D. a decrease in the quantity of grapefruit supplied.

C. a decrease in the quantity of grapefruit demanded.

Assume that China has a comparative advantage in producing corn and exports corn to Japan. We can conclude that China also has an absolute advantage in producing corn relative to Japan. China has a lower opportunity cost of producing corn relative to Japan. Japan has an absolute disadvantage in producing corn relative to China. Labor costs are higher for corn producers in Japan than in China.

China has a lower opportunity cost of producing corn relative to Japan.

) Which of the following statements is true?A) Consumer surplus measures the total benefit from participating in a market. B) When a market is in equilibrium consumer surplus equals producer surplus. C) Consumer surplus measures the net benefit from participating in a market. D) Producer surplus measures the total benefit received by producers from participating in a market.

Consumer surplus measures the net benefit from participating in a market

Which of the following statements is true? Consumer surplus measures the total benefit from participating in a market. When a market is in equilibrium consumer surplus equals producer surplus. Consumer surplus measures the net benefit from participating in a market. Producer surplus measures the total benefit received by producers from participating in a market.

Consumer surplus measures the net benefit from participating in a market.

Let D = demand, S = supply, P = equilibrium price, and Q = equilibrium quantity. What happens in the market for walnuts if the Centers for Disease Control and Prevention announces that consuming a half cup of walnuts each week helps to lower levels of bad cholesterol? D increases, S no change, P and Q increase. S increases, D no change, P decreases, Q increases. D and S increase, P and Q decrease. D no change, S increases, P decreases, Q decreases.

D increases, S no change, P and Q increase.

Markets promoteA) equity and competition.B) voluntary exchange and equality.C) equity and equality.D) competition and voluntary exchange.

D) competition and voluntary exchange.

Making "how much" decisions involvesA) calculating the total benefits of the activity and determining if you are satisfied with that amount.B) calculating the total costs of the activity and determining if you can afford to incur that expenditure.C) calculating the average benefit and the average cost of an activity to determine if it is worthwhile undertaking that activity. D) determining the additional benefits and the additional costs of that activity

D) determining the additional benefits and the additional costs of that activity

If the production possibilities frontier is ________, then opportunity costs are constant as more of one good is produced. A) bowed outB) bowed inC) non-linear If the production possibilities frontier is ________, then opportunity costs are constant as more of one good is produced. D) linear

D) linear

Which of the following is a flow in the circular flow model?A) the flow of goods and services from households to firmsB) the flow of profit and the flow of revenueC) the flow of income earned by firms and the flow of expenditures earned by households D) the flow of revenue received by firms and the flow of payments to resource owners

D) the flow of revenue received by firms and the flow of payments to resource owners

The attainable production points on a production possibilities frontier areA) the horizontal and vertical intercepts.B) the points on the production possibilities frontier.C) the points outside the area enclosed by the production possibilities frontier.D) the points on and inside the production possibility frontier.

D) the points on and inside the production possibility frontier.

An increase in population would be represented by a movement from A to B. B to A. D1 to D2. D2 to D1.

D1 to D2.

is maximized in a competitive market when marginal benefit equals marginal cost. Deadweight loss Marginal profit Economic surplus Selling price

Economic surplus

Which of the following statements is true? Any time you have to decide which action to take you are experiencing economic equity. Trade-offs do not apply when the consumers purchase a product for which there is excess supply, such as with a stock clearance sale. Every individual, no matter how rich or poor, is faced with situations that require trade-offs. Economics is a social science that studies the trade-offs we are forced to make because resources are unlimited.

Every individual, no matter how rich or poor, is faced with situations that require trade-offs.

How are the fundamental economic questions answered in a market economy? The government alone decides the answers. Individuals, firms, and the government interact in markets to decide the answers to these questions. Households and firms interact in markets to decide the answers to these questions. Large corporations alone decide the answers.

Households and firms interact in markets to decide the answers to these questions.

Which of the following is a positive economic statement? The standard of living in the United States should be higher. If the price of iPhones falls, a larger quantity of iPhones will be purchased. The government should revamp the health care system. The U.S. government should not have bailed out U.S. auto manufacturers.

If the price of iPhones falls, a larger quantity of iPhones will be purchased.

Which of the following statements about the economic decisions consumers, firms, and the government have to make is false? Governments face the problem of scarcity in making economic decisions. Only individuals face scarcity; firms and the government do not. Both firms and individuals face scarcity. Each faces the problem of scarcity which necessitates trade-offs in making economic decisions.

Only individuals face scarcity; firms and the government do not.

Which of the following statements about scarcity is true? Scarcity refers to the situation in which unlimited wants exceed limited resources. Scarcity is not a problem for the wealthy. Scarcity is only a problem when a country has too large a population. Scarcity only arises when there is a wide disparity in income distribution.

Scarcity refers to the situation in which unlimited wants exceed limited resources.

Assume there is a shortage in the market for digital music players. Which of the following statements correctly describes this situation? The demand for digital music players is greater than the supply of digital music players. Some consumers will be unable to obtain digital music players at the market price and will have an incentive to offer to buy the product at a higher price. The price of digital music players will rise in response to the shortage; as the price rises the quantity demanded will increase and the quantity supplied will decrease. The shortage will cause a decrease in the equilibrium price of digital music players.

Some consumers will be unable to obtain digital music players at the market price and will have an incentive to offer to buy the product at a higher price.

Which of the following is motivated by an equity concern? Correct! Some states have transferred funds to food bank programs in order to increase benefits to lower-income families. Following the implementation of subsidies for energy conservation, household demand for rooftop solar panels increased quite significantly in California. The United Network for Organ Sharing advocates a system of rationing scarce kidneys that would favor young patients over old in an effort to wring more life out of donated organs. The United States offers patent protection to pharmaceutical manufacturers to prevent others from duplicating their products.

Some states have transferred funds to food bank programs in order to increase benefits to lower-income families.

Which of the following is evidence of a surplus of bananas? Firms raise the price of bananas. The price of bananas is lowered in order to increase sales. The equilibrium price of bananas rises due to an increase in demand. The quantity of bananas demanded is greater than the quantity supplied.

The price of bananas is lowered in order to increase sales.

Which of the following is a normative economic statement? The price of gasoline is too high. The current high price of gasoline is the result of strong worldwide demand. When the price of gasoline rises, the quantity of gasoline purchased falls. When the price of gasoline rises, transportation costs rise.

The price of gasoline is too high.

Danielle Ocean pays for monthly pool maintenance for her home swimming pool. Last week, the owner of the pool service informed Danielle that he will have to raise his monthly service fee because of increases in the price of pool chemicals. How is the market for pool maintenance services affected by this? There is an increase in the supply of pool maintenance services. There is a decrease in the demand for pool maintenance services. There is a decrease in the quantity of pool maintenance services supplied. There is a decrease in the supply of pool maintenance services.

There is a decrease in the supply of pool maintenance service

Danielle Ocean pays for monthly pool maintenance for her home swimming pool. Last week, the owner of the pool service informed Danielle that he will have to raise his monthly service fee because of increases in the price of pool chemicals. How is the market for pool maintenance services affected by this? There is an increase in the supply of pool maintenance services. There is a decrease in the demand for pool maintenance services. There is a decrease in the quantity of pool maintenance services supplied. There is a decrease in the supply of pool maintenance services.

There is a decrease in the supply of pool maintenance services.

Which of the following is a macroeconomic question? What determines the growth rate of gross domestic product? How is the production quantity of snowboards determined? What factors determine the price of electronic cigarettes? What determines the salaries of Wall Street executives?

What determines the growth rate of gross domestic product?

The three fundamental questions that any economy must address are: What will be the prices of goods and services; how will these goods and services be produced; and who will receive them?What goods and services to produce; how will these goods and services be produced; and who receives them? Who gets jobs; what wages do workers earn; and who owns what property? How much will be saved; what will be produced; and how can these goods and services be fairly distributed?

What goods and services to produce; how will these goods and services be produced; and who receives them?

he basic economic problem of ________ has always existed and will continue to exist.A) scarcityB) efficiencyC) inflationD) recession

a

A decrease in the demand for soft drinks due to changes in consumer tastes, accompanied by an increase in the supply of soft drinks as a result of reductions in input prices, will result in a decrease in the equilibrium quantity of soft drinks and no change in the equilibrium price. a decrease in the equilibrium price of soft drinks and no change in the equilibrium quantity. a decrease in the equilibrium price of soft drinks; the equilibrium quantity may increase or decrease. an increase in the equilibrium quantity of soft drinks; the equilibrium price may increase or decrease.

a decrease in the equilibrium price of soft drinks; the equilibrium quantity may increase or decrease.

Which of the following will shift the demand curve for a good? A. a change in the technology used to produce the good B. an increase in the price of the good C. a decrease in the price of a complementary good D. a decrease in the price of the good

a decrease in the price of a complementary good

If opportunity costs are constant, the production possibilities frontier would be graphed as a ray from the origin. a positively sloped straight line. a negatively sloped curve bowed in toward the origin. a negatively sloped straight line.

a negatively sloped straight line

Rent control is an example of a subsidy for low-skilled workers. a price floor. a price ceiling. an illicit market.

a price ceiling.

The idea that because of scarcity, producing more of one good or service means producing less of another good or service refers to the economic concept of optimization. efficiency. a trade-off. equity.

a trade-off.

Consider the following statements:a. Car owners purchase more gasoline from a gas station that sells gasoline at a lower price than other rival gas stations in the area.b. Banks do not take steps to increase security since they believe it is less costly to allow some bank robberies than to install expensive security monitoring equipment.c. Firms produce more of a particular DVD when its selling price rises. Which of the above statements demonstrates that economic agents respond to incentives?

a, b, and c

The area ________ the market supply curve and ________ the market price is equal to the total amount of producer surplus in a market. above; above above; below below; above below; below

above; below

When production reflects consumer preferences, ________ occurs. allocative efficiency productive efficiency equity efficient central planning

allocative efficiency

The revenue received from the sale of ________ of a product is a marginal benefit to the firm. an additional unit the total number of units no units only profitable units

an additional unit

Assume that potatoes are an inferior good. Which of the following would cause both the equilibrium price and equilibrium quantity of potatoes to decrease? an increase in consumer income a freeze that sharply reduces potato output a decrease in consumer income a technological advancement that results in a bumper crop of potatoes

an increase in consumer income

Which of the following would cause an increase in the supply of peanut butter? a decrease in the price of grape jelly (assuming that peanut butter and grape jelly are complements) an increase in the price of peanut butter an increase the price of a product that producers sell instead of peanut butter an increase in the number of firms that produce peanut butter

an increase in the number of firms that produce peanut butter

Which of the following would cause an increase in the supply of peanut butter? a decrease in the price of grape jelly (assuming that peanut butter and grape jelly are complements) an increase in the price of peanut butter an increase the price of a product that producers sell instead of peanut butter an increase in the number of firms that produce peanut butter

an increase in the number of firms that produce peanut butter

Economists assume that individuals behave in unpredictable ways. will never take actions to help others. prefer to live in a society that values fairness above all else. are rational and respond to incentives.

are rational and respond to incentives.

Whenever a buyer and a seller agree to trade, the agreement is made based on absolute advantage. they must have identical opportunity costs in producing their respective products. one party will always be worse off. both must believe they will be made better off.

both must believe they will be made better off.

Suppose the demand curve for a product is vertical and the supply curve is upward sloping. If a per-unit tax is imposed in the market for this product sellers bear the entire burden of the tax. buyers bear the entire burden of the tax. the tax burden will be shared equally between buyers and sellers. buyers share the burden of the tax with government.

buyers bear the entire burden of the tax.

An economic principle that explains why countries produce different goods and services is absolute advantage. trade as a percentage of GDP. comparative advantage. NAFTA.

comparative advantage.

Which of the following generates productive efficiency? competition among sellers competition among buyers government inspectors government production rules and regulations

competition among sellers

Markets promote equity and competition. voluntary exchange and equality. equity and equality. competition and voluntary exchange.

competition and voluntary exchange.

The difference between the highest price a consumer is willing to pay for a good and the price the consumer actually pays is called producer surplus. the substitution effect. the income effect. consumer surplus.

consumer surplus

Last year, the Pottery Palace supplied 8,000 ceramic pots at $40 each. This year, the company supplied the same quantity of ceramic pots at $55 each. Based on this evidence, The Pottery Palace has experienced a decrease in supply. an increase in supply. an increase in the quantity supplied. a decrease in the quantity supplied.

decrease in supply

If a demand curve shifts to the left, then a. demand has increased. b. quantity demanded has increased. c. demand has decreased. d. quantity demanded has decreased.

demand has decreased.

n economics, the term "equity" meansA) everyone has an equal standard of living.B) the hardest working individuals consume all they want.C) only elected officials have high standards of living.D) economic benefits are distributed fairly.

economic benefits are distributed fairly.

Productive efficiency is achieved when firms add a low profit margin to the goods and services they produce. firms produce the goods and services that consumers value most. firms produce goods and services at the lowest cost. there are no shortages or surpluses in the market.

firms produce goods and services at the lowest cost.

The production possibilities frontier model shows that if consumers decide to buy more of a product, its price will increase. a market economy is more efficient in producing goods and services than is a centrally planned economy. economic growth can only be achieved by free market economies. if all resources are fully and efficiently utilized, more of one good can be produced only by producing less of another good.

if all resources are fully and efficiently utilized, more of one good can be produced only by producing less of another good.

A production possibilities frontier with a bowed-outward shape indicates the possibility of inefficient production. constant opportunity costs as more and more of one good is produced. increasing opportunity costs as more and more of one good is produced. decreasing opportunity costs as more and more of one good is produced.

increasing opportunity costs as more and more of one good is produced.

A supply schedule

is a table that shows the relationship between the price of a product and the quantity of the product supplied.

In a perfectly competitive market, there are ________ buyers and ________ sellers. many; few few; many many; many few; few

many; many

In economics, the term ________ means "additional" or "extra." allocative marginal equity optimal

marginal

In economics, the term ________ refers to a group of buyers and sellers of a product and the arrangement by which they come together to trade. collective cooperative market trade-off

market

The demand by all the consumers of a given good or service is the ________ for the good or service.

market demand

The production possibilities frontier shows the ________ combinations of two products that can be produced in a particular time period with available resources. minimum attainable maximum attainable only equitable

max attainable

To affect the market outcome, a price ceiling must be set below the illicit market price. must be set below the legal price. must be set below the price floor. must be set below the equilibrium price.

must be set below the equilibrium price.

To affect the market outcome, a price ceilingA) must be set below the illicit market price. B) must be set below the legal price. C) must be set below the price floor. D) must be set below the equilibrium price.

must be set below the equilibrium price.

All of the following are part of an economic model except assumptions. hypotheses. data. opinions.

opinions

The highest-valued alternative that must be given up to engage in an activity is the definition of economic equity. marginal benefit. opportunity cost. marginal cost.

opportunity cost.

By drawing a demand curve with ________ on the vertical axis and ________ on the horizontal axis, economists assume that the most important determinant of the demand for a good is the ________ of the good. A quantity; price; quantity B. price; quantity; quantity C. price; quantity; price D. quantity; price; price

price; quantity; price

In economics, choices must be made because we live in a world of unemployment. scarcity. greed. unlimited resources.

scarcity

HouseholdsA) have no involvement in the circular flow in a market economy.B) purchase resources in the factor market.C) sell goods in the product market.D) sell resources in the factor market.

sell resources in the factor market.

34) Suppose the demand curve for a product is horizontal and the supply curve is upward sloping. If a per-unit tax is imposed in the market for this productA) sellers bear the entire burden of the tax. B) the tax burden will be shared among the government, buyers, and sellers.C) buyers bear the entire burden of the tax.D) the tax burden will be shared by buyers and sellers.

sellers bear the entire burden of the tax.

Suppose the demand curve for a product is horizontal and the supply curve is upward sloping. If a per-unit tax is imposed in the market for this product sellers bear the entire burden of the tax. the tax burden will be shared among the government, buyers, and sellers. buyers bear the entire burden of the tax. the tax burden will be shared by buyers and sellers.

sellers bear the entire burden of the tax.

Suppose that when the price of strawberries decreases, Simone increases her purchase of whipped cream. To Simone A. strawberries and whipped cream are complements. B. strawberries and whipped cream and substitutes. C. strawberries and whipped cream are normal goods. D. strawberries are a normal good and whipped cream is an inferior good.

strawberries and whipped cream are complements.

Tomas increased his consumption of potato chips when the price of pistachios increased. For Tomas, potato chips and pistachios are

substitutes

1) The athletic shoe industry is highly competitive. In recent years, companies like Allbirds and Skechers began offering shoes made of different materials or in different styles to better compete with industry giants Nike and Adidas. These new styles of athletic shoes that are being marketed to compete with shoes by Nike and Adidas would be considered A. complements to shoes by Nike and Adidas. B. substitutes for shoes by Nike and Adidas. C. inferior goods compared to the shoes by Nike and Adidas. D. normal goods compared to shoes by Nike and Adidas

substitutes for shoes by Nike and Adidas

he actual division of the burden of a tax between buyers and sellers in a market is called tax incidence. tax liability. tax bearer. tax parity.

tax incidence.

Marginal cost is the total cost of producing one unit of a good or service. the average cost of producing a good or service. the difference between the lowest price a firm would have been willing to accept and the price it actually receives. the additional cost to a firm of producing one more unit of a good or service.

the additional cost to a firm of producing one more unit of a good or service.

If a firm expects that the price of its product will be higher in the future than it is today, then the firm will go out of business. the firm has an incentive to increase supply now and decrease supply in the future. the firm has an incentive to decrease quantity supplied now and increase quantity supplied in the future. the firm has an incentive to decrease supply now and increase supply in the future.

the firm has an incentive to decrease supply now and increase supply in the future.

Who, in a centrally planned economy, decides what goods and services will be produced with the scarce resources available in that economy? the government producers consumers consumers and producers

the government

Economic efficiency in a competitive market is achieved when economic surplus is equal to consumer surplus. consumers and producers are satisfied. the marginal benefit equals the marginal cost from the last unit sold. producer surplus equals the total amount firms receive from consumers minus the cost of production.

the marginal benefit equals the marginal cost from the last unit sold.

Consumers are willing to purchase a product up to the point where the marginal benefit of consuming the product is equal to the marginal cost of consuming it. the consumer surplus is equal to the producer surplus. the marginal benefit of consuming the product equals the area below the supply curve and above the market price. the marginal benefit of consuming a product is equal to its price.

the marginal benefit of consuming a product is equal to its price.

Willingness to pay measures the maximum price a buyer is willing to pay for a product minus the amount the buyer actually pays for it. the amount a seller actually receives for a good minus the minimum amount the seller is willing to accept for the good. the maximum price that a buyer is willing to pay for a good or service. the maximum price a buyer is willing to pay minus the minimum price a seller is willing to accept.

the maximum price that a buyer is willing to pay for a good or service.

The income effect of a price change refers to the impact of a change in A. income on the price of a good. B. demand when income changes. C. the quantity demanded when income changes. D. the price of a good on a consumer's purchasing power.

the price of a good on a consumer's purchasing power.

A change in all of the following variables will change the market demand for a product except A. the price of the product. B. population and demographics. C. income. D. tastes.

the price of the product.

The law of demand implies, holding everything else constant, that as the price of bagels increases a. the quantity of bagels demanded will decrease. b. the demand for bagels will decrease. c. the quantity of bagels demanded will increase. d.the demand for bagels will increase.

the quantity of bagels demanded will decrease

Which of the following is a result of a market economy? environmental protection an equal income distribution agreement on equity voluntary exchange

voluntary exchange