Microeconomics 18th Edition by Campbell McConnell, Stanley Brue, Sean Flynn

Exercise 14

Many apartment-complex owners are installing water meters for each individual apartment and billing the occupants according to the amount of water they use. This is in contrast to the former procedure of having a central meter for the entire complex and dividing up the water expense as part of the rent. Where individual meters have been installed, water usage has declined 10 to 40 percent. Explain this drop, referring to price and marginal utility.