Editing Price discrimination (section)

===Second degree: quantity discount===
In second-degree price discrimination, the price of the same good varies according to the quantity demanded. It usually comes in the form of  a quantity discount that exploits the law of diminishing [[marginal utility]]. Diminishing marginal utility claims that consumer utility decreases (diminish) with each successive unit consumed (think [[Bonbon|bonbons]]).<ref name=":22" /> By offering a quantity discount for a larger quantity the seller is able to capture some of the consumer surplus.<ref name=":12" /> This is because diminishing marginal utility may mean the consumer would not be willing to purchase an additional unit without a discount since the marginal utility received from the good or service is no longer greater than the price.<ref name=":22" /> However, by offering a discount the seller can capture some of consumers surplus by encouraging them to purchase an additional unit at a discounted price.<ref name=":12" /> This is particularly widespread in sales to industrial customers, where bulk buyers enjoy discounts.<ref>Frank, Robert H. (2010): ''Microeconomics and Behavior'', 8th ed., McGraw-Hill Irwin, p. 395. {{ISBN?}}</ref>

Mobile phone plans and subscriptions are instances of second-degree price discrimination. Consumers usually require a one-year subscription to be less expensive than a monthly one. Whether or not consumers need the longer subscription, they are more likely to accept one if the cost is less.<ref>{{Cite journal |last1=Lahiri |first1=Atanu |last2=Dewan |first2=Rajiv M |last3=Freimer |first3=Marshall |year=2013 |title=Pricing of Wireless Services: Service Pricing vs. Traffic Pricing |url=https://www.jstor.org/stable/42004312 |journal=Information Systems Research |volume=24 |issue=2 |pages=418–435 |doi=10.1287/isre.1120.0434 |jstor=42004312 }}</ref>