Key Concepts and Summary

Key Terms

allocative efficiency when the mix of goods produced represents the mix that society most desires budget constraint all possible consumption combinations of goods that someone can afford, given the prices of goods, when all income is spent; the boundary of the opportunity set comparative advantage when a country can produce a good at a lower cost in terms of other goods; or, when a country has a lower opportunity cost of production invisible hand Adam Smith's concept that individuals' self-interested behavior can lead to positive social outcomes law of diminishing marginal utility as we consume more of a good or service, the utility we get from additional units of the good or service tends to become smaller than what we received from earlier units law of diminishing returns as we add additional increments of resources to producing a good or service, the marginal benefit from those additional increments will decline marginal analysis examination of decisions on the margin, meaning a little more or a little less from the status quo normative statement statement which describes how the world should be opportunity cost measures cost by what we give up/forfeit in exchange; opportunity cost measures the value of the forgone alternative opportunity set all possible combinations of consumption that someone can afford given the prices of goods and the individual’s income positive statement statement which describes the world as it is production possibilities frontier (PPF) a diagram that shows the productively efficient combinations of two products that an economy can produce given the resources it has available. productive efficiency when it is impossible to produce more of one good (or service) without decreasing the quantity produced of another good (or service) sunk costs costs that we make in the past that we cannot recover utility satisfaction, usefulness, or value one obtains from consuming goods and services

Key Concepts and Summary

2.1 How Individuals Make Choices Based on Their Budget Constraint

Economists see the real world as one of scarcity: that is, a world in which people’s desires exceed what is possible. As a result, economic behavior involves tradeoffs in which individuals, firms, and society must forgo something that they desire to obtain things that they desire more. Individuals face the tradeoff of what quantities of goods and services to consume. The budget constraint, which is the frontier of the opportunity set, illustrates the range of available choices. The relative price of the choices determines the slope of the budget constraint. Choices beyond the budget constraint are not affordable. Opportunity cost measures cost by what we forgo in exchange. Sometimes we can measure opportunity cost in money, but it is often useful to consider time as well, or to measure it in terms of the actual resources that we must forfeit. Most economic decisions and tradeoffs are not all-or-nothing. Instead, they involve marginal analysis, which means they are about decisions on the margin, involving a little more or a little less. The law of diminishing marginal utility points out that as a person receives more of something—whether it is a specific good or another resource—the additional marginal gains tend to become smaller. Because sunk costs occurred in the past and cannot be recovered, they should be disregarded in making current decisions.

2.2 The Production Possibilities Frontier and Social Choices

A production possibilities frontier defines the set of choices society faces for the combinations of goods and services it can produce given the resources and the technology that are available. The shape of the PPF is typically curved outward, rather than straight. Choices outside the PPF are unattainable and choices inside the PPF are wasteful. Over time, a growing economy will tend to shift the PPF outwards. The law of diminishing returns holds that as increments of additional resources are devoted to producing something, the marginal increase in output will become increasingly smaller. All choices along a production possibilities frontier display productive efficiency; that is, it is impossible to use society’s resources to produce more of one good without decreasing production of the other good. The specific choice along a production possibilities frontier that reflects the mix of goods society prefers is the choice with allocative efficiency. The curvature of the PPF is likely to differ by country, which results in different countries having comparative advantage in different goods. Total production can increase if countries specialize in the goods in which they have comparative advantage and trade some of their production for the remaining goods.

2.3 Confronting Objections to the Economic Approach

The economic way of thinking provides a useful approach to understanding human behavior. Economists make the careful distinction between positive statements, which describe the world as it is, and normative statements, which describe how the world should be. Even when economics analyzes the gains and losses from various events or policies, and thus draws normative conclusions about how the world should be, the analysis of economics is rooted in a positive analysis of how people, firms, and governments actually behave, not how they should behave.

Self-Check Questions

1 . Suppose Alphonso’s town raised the price of bus tickets from $0.50 per trip to $1 per trip (while the price of burgers stayed at $2 and his budget remained $10 per week.) Draw Alphonso’s new budget constraint. What happens to the opportunity cost of bus tickets? 2 . Return to the example in Figure 2.4. Suppose there is an improvement in medical technology that enables more healthcare with the same amount of resources. How would this affect the production possibilities curve and, in particular, how would it affect the opportunity cost of education? 3 . Could a nation be producing in a way that is allocatively efficient, but productively inefficient? 4 . What are the similarities between a consumer’s budget constraint and society’s production possibilities frontier, not just graphically but analytically? 5 . Individuals may not act in the rational, calculating way described by the economic model of decision making, measuring utility and costs at the margin, but can you make a case that they behave approximately that way? 6 . Would an op-ed piece in a newspaper urging the adoption of a particular economic policy be a positive or normative statement? 7 . Would a research study on the effects of soft drink consumption on children’s cognitive development be a positive or normative statement?

Review Questions

8 . Explain why scarcity leads to tradeoffs. 9 . Explain why individuals make choices that are directly on the budget constraint, rather than inside the budget constraint or outside it. 10 . What is comparative advantage? 11 . What does a production possibilities frontier illustrate? 12 . Why is a production possibilities frontier typically drawn as a curve, rather than a straight line? 13 . Explain why societies cannot make a choice above their production possibilities frontier and should not