Price Discrimination Extended Essay


Professor Preston McAfee on Price Discrimination

(you must have RealPlayer to view this video. Mac users can download it here)

CalTech Economics professor Preston McAfee is an expert on prices. His research spans three decades and examines the pricing behavior of firms in various market structures. In the lecture linked above the professor shares several examples of firms practicing price discrimination. I was surprised to see that many of the examples he discusses are ones that I have been using in my own lectures on price discrimination for the last few years.

McAfee presents a mathematical formula for monopoly pricing, which no AP or IB text that I’ve seen has included:

Monopoly Price = [PED/(1-PED)]x MCwhere PED is the price elasticity of demand of the customer and MC is the firm’s marginal cost of production.

The basic idea is that the more inelastic the customer’s demand, the higher price the monopolist should charge over its marginal cost. The implication, therefore, is that a monopolist prefers to charge higher prices to customer’s whose demand is inelastic and lower prices to customers who are “price sensitive” or whose demand is elastic. The charging of different prices to different consumers for the exact same product is what economists call price discrimination.

McAfee begins talking about price discrimination at minute 8:44 in the video. His examples include:

  • Movie theaters: Charge different prices based on age. Seniors and youth pay less since they tend to be more price sensitive.
  • Gas stations: Gas stations will charge different prices in different neighborhoods based on relative demand and location.
  • Grocery stores: Offer coupons to price sensitive consumers (people whose demand is inelastic won’t bother to cut coupons, thus will pay more for the same products as price sensitive consumers who take the time to collect coupons).
  • Quantity discounts: Grocery stores give discounts for bulk purchases by customers who are price sensitive (think “buy one gallon of milk, get a second gallon free”… the family of six is price sensitive and is likely to pay less per gallon than the dual income couple with no kids who would never buy two gallons of milk).
  • Dell Computers: Dell price discriminates based on customer answers to questions during the online shopping process. Dell charges higher prices to large business and government agencies than to households and small businesses for the exact same product!
  • Hotel room rates: Some hotels will charge less for customers who bother to ask about special room rates than to those who don’t even bother to ask.
  • Telephone plans: Some customers who ask their provider for special rates will find it incredibly easy to get better calling rates than if they don’t bother to ask.
  • Damaged goods discounts: When a company creates  and sells two products that are essentially identical except one has fewer features and costs significantly less to capture more price-sensitive consumers.
  • Book publishers: Some paperbacks cost more to manufacture but sell to consumers for significantly less than hard covers. Price sensitive consumers will buy the paperback while those with inelastic demand will pay more for the hard cover.
  • Airline ticket prices: Weekend stayover discounts for leisure travelers mean business people, whose demand for flights is highly inelastic, but who will rarely stay over a weekend, pay far more for a roundtrip ticket that departs and returns during the week.

McAfee also goes into a fascinating discussion of price dispersion which is essentially a theory of oligopoly pricing. All Econ teachers should watch this video and find examples of price discrimination and oligopoly pricing that they can incorporate into their own class.

If you’re up for a challenge, try deciphering some of the mathematics in McAfee’s free, downloadable intro to economics text, available here.

About the author:  Jason Welker teaches International Baccalaureate and Advanced Placement Economics at Zurich International School in Switzerland. In addition to publishing various online resources for economics students and teachers, Jason developed the online version of the Economics course for the IB and is has authored two Economics textbooks: Pearson Baccalaureate’s Economics for the IB Diploma and REA’s AP Macroeconomics Crash Course. Jason is a native of the Pacific Northwest of the United States, and is a passionate adventurer, who considers himself a skier / mountain biker who teaches Economics in his free time. He and his wife keep a ski chalet in the mountains of Northern Idaho, which now that they live in the Swiss Alps gets far too little use. Read more posts by this author
  1. Hey

    I'm doing my EE in economics; price discrimination to be specific. Basically the data I've collected is the price for products in three different Carrefour outlets - one in Singapore (in the heart of the city), and two in two different areas in Taipei. The first Taipei Carrefour is located in the "expat area" while the other is surrounded by warehouses and close to Costco. What I found is that the price differs for the same product (eg 2litre 7-Up bottle) in all three outlets.

    The three problems I face are:

    1. I don't have a question for my title.
    2. Pretty much the only products that are sold in all three outlets are food.
    3. Not many products show the differing prices; Singapore prices are almost always different from Taipei prices but the two Carrefours in Taipei quote the same price for the same product fairly often.

    My EE supervisor is really lazy so he hasn't replied to any of my e-mails this summer; I just e-mailed the other economics teacher for help but I'm not sure if he will lend a hand. What am I to do???

    Last edited by stabilosmith; 29-07-2009 at 12:35.
  2. Clearly there is a problem in your approach, price discrimination exists only within the economy not between economies, thats Purchasing power, importing taxes and standard of living that we are talking abt that makes the differences of prices in singapore and taipei. Obviously if your two prices in taipei are the same, there isnt any price discrimination then!!!

  3. Well the prices DO differ in the two Taipei Carrefour outlets for some products, just not that many. If the price is not the same, then, yeah, duh... Hahaha.

    Do you think I would be able to get around the whole purchasing power issue by making my question "What evidence supports that Carrefour practices price discrimination?" and using your point as a sort of counter-argument? Would that work?

One thought on “Price Discrimination Extended Essay

Leave a Reply

Your email address will not be published. Required fields are marked *