The Price Elasticity of Demand for Subway and Bus Rides

Supports: Microeconomics, Chapter 6, Section 6.3, Economics, Chapter 6, Section 6.3, and Essentials of Economics, Chapter 7, Section 7.7.

New York City subway. (Photo from the New York Times.)

An article on Crain’s New York Business noted that the Metropolitan Transit Authority (MTA), which runs New York City’s public transportation system was increasing the fare for a bus or subway ride from $2.75 to $2.90. The article noted that: “Revenue generated by the fare increase is expected to cover the [MTA’s] operating expenses and help keep up with inflation.”

a.  What is the MTA assuming about the price elasticity of demand for subway and bus rides in New York City? How plausible do you find this assumption? Briefly explain.

b. What is the largest percentage decline in subway and bus rides that the MTA can experience and still meet its revenue expectations?

Solving the Problem

Step 1:  Review the chapter material. This problem is about the relationship between a price increase on quantity demanded and revenue, so you may want to review the section “The Relationship between Price Elasticity of Demand and Total Revenue.”

Step 2:  Answer part (a) by explaining what the MTA is assuming about the price elasticity of demand for subway and bus rides, and comment on the plausibility of this assumption. If the MTA is expecting that an increase in the price of a subway and bus ride will increase the total revenue it earns from these rides, it must be assuming that the demand for subway and bus rides is price inelastic. If the demand were price elastic, the MTA would earn less revenue following the price increase.

 As we saw in Chapter 6, Section 6.2, the most important determinant of elasticity is the existence of substitutes. In a big city, the most important substitutes to taking public transportation are: (1) people walking, (2) people driving their own cars, or (3) people using a ride-hailing service, such as Uber and Lyft.  People who live close to their destination and who were indifferent between walking and taking public transportation before the price increase, are likely to switch to walking. Given the size of a city like New York, we might expect the number of these people to be relatively small. Driving your own car in a big city has the drawback that heavy traffic may mean it takes longer to drive than to take the bus or subway and paying for parking can be expensive. Using Uber or Lyft is also much more expensive than taking public transportation and may also be slow. It seems likely that current users of public transportation in New York City don’t see these alternatives as close substitutes for the bus or subway. So, it’s plausible for the MTA to assume that the demand for subway and bus rides is price inelastic. 

Step 3:  Answer part (b) by calculating the largest percentage decline in bus and subway rides that the MTA can experience and still meet its revenue expectations. The MTA is increasing the price of subway and bus rides from $2.75 to $2.90 per ride. That is a ($0.15/$2.75) × 100 = 5.5 percent increase. (Note that we would get a somewhat different result if we used the midpoint formula described in Section 6.1.) For the MTA’s revenue to increase as a result of the price increase, the percentage decrease in the quantity demanded of subway rides must be less than the percentage increase in the price. Therefore, the price increase can’t result in a decline of more than 5.5 percent. 

Source:  Caroline Spivak, “Subway and Bus Fares Will Increase Starting Sunday,” crainesnewyork.com, August 18, 2023.