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Chapter 13: Positive Externalities and Public Goods

8 problems · 0 figures

13-1 §13.1 source ↗

Do market demand curves reflect positive externalities? Why or why not?

Answer

No. A market demand curve reflects only the private benefits of those who are consuming the product. Positive externalities are benefits that spill over to third parties, so they create social benefits, and are not captured by a market (or private benefit) demand curve.

13-2 §13.1 source ↗

Suppose that Sony's R&D investment in digital devices has increased profits by 20%. Is this a private or social benefit?

Answer

Clearly Samsung is benefiting from the investment, so the 20% increase in profits is a private benefit. If Samsung is unable to capture all of the benefit, perhaps because other companies quickly copy and produce close substitutes, then Samsung’s investment will produce social benefits.

13-3 §13.1 source ↗

Table 13.4 in the book ↗
Estimated Rate of ReturnPrivate profits of the firm from an R&D project (in $ millions)
10%$100
9%$102
8%$108
7%$118
6%$133
5%$153
4%$183
3%$223

The Gizmo Company is planning to develop new household gadgets. Table 13.4 shows the company’s demand for financial capital for research and development of these gadgets, based on expected rates of return from sales. Now, say that every investment would have an additional 5% social benefit—that is, an investment that pays at least a 6% return to the Gizmo Company will pay at least an 11% return for society as a whole; an investment that pays at least 7% for the Gizmo Company will pay at least 12% for society as a whole, and so on. Answer the questions that follow based on this information.

a. If the going interest rate is 9%, how much will Gizmo invest in R&D if it receives only the private benefits of this investment?

b. Assume that the interest rate is still 9%. How much will the firm invest if it also receives the social benefits of its investment? (Add an additional 5% return on all levels of investment.)

Answer

a. $102 million.

b. If the interest rate is 9%, the cost of financial capital, and the firm can capture the 5% return to society, the firm would invest as if its effective rate of return is 4%, so it will invest $183 million.

13-4 §13.1 source ↗

The Junkbuyers Company travels from home to home, looking for opportunities to buy items that would otherwise end up with the garbage, but which the company can resell or recycle. Which will be larger, the private or the social benefits?

Answer

When the Junkbuyers Company purchases something for resale, presumably both the buyer and the seller benefit—otherwise, they would not need to make the transaction. However, the company also reduces the amount of garbage produced, which saves money for households and/or for the city that disposes of garbage. So the social benefits are larger than the private benefits.

13-5 §13.2 source ↗

When residents in a neighborhood tidy it and keep it neat, there are a number of positive spillovers: higher property values, less crime, happier residents. What types of government policies can encourage neighborhoods to clean up?

Answer

Government programs that either pay for neighborhood clean-up directly or that provide reduced tax payments for those who clean up or fix up their own property could be enacted. It is also easy to imagine how a city might allow its businesses to form a group that would pay for and manage neighborhood cleanup.

13-6 §13.2 source ↗

Education provides both private benefits to those who receive it and broader social benefits for the economy as a whole. Think about the types of policies a government can follow to address the issue of positive spillovers in technology and then suggest a parallel set of policies that governments could follow for addressing positive externalities in education.

Answer

Government programs that either pay for education directly or that provide loans or reduced tax payments for education could create positive spillovers. A city might allow its businesses to form a group that would coordinate business efforts with schools and local colleges and universities—allowing students to obtain real-world experience in their chosen fields and providing businesses with enthusiastic, trained workers.

13-7 §13.3 source ↗

Which of the following goods or services are nonexcludable?

a. police protection

b. streaming music from satellite transmission programs

c. roads

d. primary education

e. cell phone service

Answer

a. Once citizens are protected from crime, it is difficult to exclude someone from this protection, so it is nonexcludable.

b. Some satellite radio services, such as SiriusXM, are sold by subscription fee, so it is excludable.

c. Once a road is built it is difficult to exclude people, although toll roads can exclude non-payers.

d. Primary education can be provided by private companies and so it is excludable.

e. Companies sell cell phone service and exclude those who do not pay.

13-8 §13.3 source ↗

Are the following goods non-rival in consumption?

a. slice of pizza

b. laptop computer

c. public radio

d. ice cream cone

Answer

a. Two people cannot enjoy the same slice of pizza at the same time, so private goods, such as a slice of pizza, are rivalrous.

b. Two people cannot use one laptop at the same time, so they are rivalrous in consumption.

c. Public radio can be heard by anyone with a radio, so many people can listen at the same time—the good is nonrivalrous.

d. It is difficult for two people to simultaneously eat an ice cream cone, so it is rivalrous in consumption.

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Problems and answers are adapted from Principles of Microeconomics 3e by Steven A. Greenlaw, David Shapiro and Daniel MacDonald, OpenStax, and are used under the CC BY-NC-SA 4.0 licence. Access for free at https://openstax.org/books/principles-microeconomics-3e/pages/1-introduction. Illustrations: Copyright Rice University, OpenStax, under CC BY-NC-SA 4.0 license. This adaptation is released under the same licence, is non-commercial, and is neither affiliated with nor endorsed by OpenStax or Rice University.