Monday, November 16, 2009

Can you tell me how to get to Sesame Street?

There are three groups in Marietta. Their demand curves for public television in hours of programming, T, are given respectively by:

W1 = $200 - T
W2 = $240 - T
W3 = $320 - 2T.

Suppose public television is a pure public good that can be produced at a constant marginal cost of $200 per hour.

a) What is the efficient number of hours of public television? Explain how you determined the answer.

b) How much public television would a competitive private market provide? Explain how you determined the answer.

Thursday, November 12, 2009

A Mankiw Quiz

The following question was posed by Harvard economist Greg Mankiw on his well-read blog. See if you can provide an answer.

Only one firm produces and sells soccer balls in the country of Wiknam, and as the story begins, international trade in soccer balls is prohibited. The following equations describe the monopolist’s demand, marginal revenue, total cost, and marginal cost:

Demand: P = 10 – Q
Marginal Revenue: MR = 10 – 2Q
Total Cost: TC = 3 + Q + 0.5 Q^2
Marginal Cost: MC = 1 + Q

where Q is quantity and P is the price measured in Wiknamian dollars.

a. How many soccer balls does the monopolist produce? At what price are they sold? What is the monopolist’s profit?

b. One day, the King of Wiknam decrees that henceforth there will be free trade—either imports or exports— of soccer balls at the world price of $6. The firm is now a price taker. What happens to domestic production of soccer balls? To domestic consumption? Does Wiknam export or import soccer balls?

c. In our analysis of international trade in Chapter 9, a country becomes an exporter when the price without trade is below the world price and an importer when the price without trade is above the world price. Does that conclusion hold in your answers to parts (a) and (b)? Explain.

d. Suppose that the world price was not $6 but, instead, happened to be exactly the same as the domestic price without trade as determined in part (a). Would anything have changed when trade was permitted? Explain.

Tuesday, November 3, 2009

Buckeyes or Wolverines?

Suppose a student athlete has two options: Play football for the Ohio State University or play football for the University of Michigan. The athlete anticipates that if he stays healthy he will play in the NFL and his salary will be $1,700,000 if he attends OSU and $1,250,000 if he attends UM. If he does not make it to the NFL, the athlete anticipates his salary will be $85,000 per year if he attends UM and $65,000 if he attends OSU. Finally, the student anticipates the odds of a career-ending injury at UM are 15% whereas at OSU the odds are 6%. Given this information, which school will the student attend, all else equal? Show all of your calculations which lead to your answer.

Congratulations to Xiaotian (Eric) Ma for being the first to figure out this week's question. In making the decision over which college to attend, a simple decision rule might be to choose the college that, on average, provides the higher expected income. The probability of injury will govern the likelihood that the young athlete will ever play professionally or settle for a regular career with his bachelor's degree.

Thus, the expected value of attending each college can be calculated as:

EV(OSU) = (0.94)($1,700,000) + (0.06)($65,000) = $1,601,900
EV(UM) = (0.85)($1,250,000) + (0.15)($85,000) = $1,075,250

As Eric points out, OSU provides the young athlete with the better income potential.