Environmental policies to address the externality of single-use plastic straws

M. Jimena González-Ramírez, Manhattan College, jimena.gonzalez@manhattan.edu
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Prior to class, students read the following news article: https://www.npr.org/sections/thesalt/2018/05/31/615580695/last-straw-for-plastic-straws-cities-restaurants-move-to-toss-these-sippers. Students learn about the externality of single-use plastic straws. Moreover, they learn about different policies to deal with this externality.

Context for Use

  • This activity should be used at the end of an externalities chapter in a principles of microeconomics course or in an environmental economics course.
  • Students should be knowledgeable about externalities, market failure, and environmental policies to internalize externalities.
  • There are no class size limitations
  • This activity will take up to a class period, depending on the discussion length.


This activity asks students to consider single-use plastic straws and their externality. Students are assigned to read a news article ( https://www.npr.org/sections/thesalt/2018/05/31/615580695/last-straw-for-plastic-straws-cities-restaurants-move-to-toss-these-sippers) prior to class. Students should be able to identify and understand the pollution externality associated with plastic straws. Since the market fails, students are asked to analyze and compare different environmental policies to decrease single-use plastic straw pollution. By having to choose the best policy, students will be able to compare costs, benefits, and trade-offs within and across different policies. Students should also consider each policy's feasibility and ease of monitoring when making their choice.

Expected Student Learning Outcomes

In this exercise, students will be able to identify a negative externality and to discuss and compare policies to deal with such externality.

Information Given to Students

Most restaurants, food trucks, bars, and coffee shops hand out plastic straws with the order of any drink without request and without any charge. Concern for single-use plastic straws is growing among different groups that are pushing for changes. For instance, the news article assigned for today summarizes different initiatives to decrease single-use plastic straw consumption: https://www.npr.org/sections/thesalt/2018/05/31/615580695/last-straw-for-plastic-straws-cities-restaurants-move-to-toss-these-sippers

Given the different proposals, what is the best way to decrease single-use plastic straw usage?

A. Ban single-use plastic straws.
B. Mandate that straws are only given out if customers explicitly request them.
C. Promote the usage of non-plastic straws made of paper, silicone, wood, metal, glass, or pasta by subsidizing these products.
D. Charge for using plastic straws.

Plastic Straw Externality AE (Microsoft Word 2007 (.docx) 15kB Jul17 18)

Teaching Notes and Tips

Prefatory Remarks:

Single-use plastics pollute our streets, landfills, and oceans. Different policies have been proposed to decrease the amount of single-use plastics, as highlighted by the article on plastic straws assigned prior to class. Your goal is to assess and compare different environmental policies aimed at decreasing pollution from single-use plastics.

Application Exercise:

Each team should report their choice simultaneously. Within each team, a student can be randomly selected to explain to answer the discussion questions. This activity can be assessed through the reasoning for choosing a policy provided by each team (first question from the discussion questions). The reasoning should be based on economic theory and economic analysis that connects course materials to the application problem.

Discussion questions:
  • What was the most important reason for your choice?
  • Why does the average consumer utilizes single-use plastic straws?
  • Are using plastic straws an example of a positive or a negative externality?
  • What is the externality in this problem?
  • Is there a market failure? Explain.
  • What are the costs and benefits of single-use plastic straws?
  • What are the social costs associated with this externality?
  • What are the individual benefits?
  • What are the costs of each policy?
  • What are the benefits of each policy?
  • How can each policy be monitored? Be enforced?
  • Which policy is easiest to implement?

Closing Remarks:
While there are trade-offs between different environmental policies, I hope this exercise allowed you to compare different policy alternatives for a very specific source of pollution: plastic straws. To conclude, write one sentence that summarizes the main lesson you learned from this team exercise.


At the end of the activity (in the same class period or at the beginning of the following period), each student will be asked to identify a negative externality different than the pollution from single-use plastic straws. Each student will be asked to identify the best policy that can internalize the chosen externality and to explain why the policy is better than other policy alternatives. This material is collected from a sample of students to determine whether the learning objectives have been met.

References and Resources

Prior to class, students should read this article about different policies to reduce plastic straws: https://www.npr.org/sections/thesalt/2018/05/31/615580695/last-straw-for-plastic-straws-cities-restaurants-move-to-toss-these-sippers