Problem
Nataraj (2007) finds that a 100% increase in the price of water for heavy users in Santa Cruz, California caused the quantity of water they demanded to fall by an average of 20%. (Before the increase, heavy users initially paid $1.55 per unit, but afterward they paid $3.14 per unit.) In percentage terms, how much did their water expenditure (price times quantity)-which is the water company's revenue-change?
The response should include a reference list. Double-space, using Times New Roman 12 pnt font, one-inch margins, and APA style of writing and citations.