Greg Mankiw's Blog

Steering into an Iceberg

noreply@blogger.com (Greg Mankiw) — Sat, 21 Nov 2009 11:46:00 +0000

Former CBO director Douglas Holtz-Eakin opines on fiscal policy.

What makes a nation rich?

noreply@blogger.com (Greg Mankiw) — Fri, 20 Nov 2009 13:10:00 +0000

The answer from MIT economist Daron Acemoglu.

Laibson in Ec 10

noreply@blogger.com (Greg Mankiw) — Fri, 20 Nov 2009 10:51:00 +0000

Every year, one of the most popular guest speakers in ec 10 is David Laibson, who gives students a clear and compelling introduction to behavioral economics. David is giving that lecture today at noon in Sanders Theater. If any other Harvard students want to attend, feel free. (If any other local blog readers want to join us, email me; we can accommodate a few others.)

Take Out Your Pencils 2

noreply@blogger.com (Greg Mankiw) — Thu, 19 Nov 2009 09:04:00 +0000

Readers seemed to enjoy my recent post of an introductory economics problem. Here is a new one for you. (I won't post the answer, so instructors can assign the problem as homework.) This one is in honor of Professor Pigou.

The town of Wiknam has 5 residents whose only activity is producing and consuming fish. They produce fish in two ways. Each person who works on a fish farm raises 2 fish per day. Each person who goes fishing in the town lake catches X fish per day. X depends on N, the number of residents fishing in the lake. In particular,

X = 6 – N.

Each resident is attracted to the job that pays more fish.

a. Why do you suppose that X, the productivity of each fisherman, falls as N, the number of fishermen, rises? What economic term would you use to describe the fish in the town lake? Would the same description apply to the fish from the farms? Explain.

b. The town’s Freedom Party thinks every individual should have the right to choose between fishing in the lake and farming without government interference. Under its policy, how many of the residents would fish in the lake and how many would work on fish farms? How many fish are produced?

c. The town’s Efficiency Party thinks Wiknam should produce as many fish as it can. To achieve this goal, how many of the residents should fish in the lake and how many should work on the farms? (Hint: Create a table that shows the number of fish produced—on farms, from the lake, and in total—for each N from 0 to 5.)

d. The Efficiency Party proposes achieving its goal by taxing each person fishing in the lake by an amount equal to T fish per day and distributing the proceeds equally among all Wiknam residents. Calculate the value of T that would yield the outcome you derived in part (c).

e. Compared with the Freedom Party’s hands-off policy, who benefits and who loses from the imposition of the Efficiency Party’s fishing tax?

Happy Birthday, Professor Pigou

noreply@blogger.com (Greg Mankiw) — Thu, 19 Nov 2009 01:27:00 +0000

Arthur Cecil Pigou was born 132 years ago today.

Flier on Healthcare Reform

noreply@blogger.com (Greg Mankiw) — Wed, 18 Nov 2009 01:42:00 +0000

Jeffrey Flier, the Dean of Harvard Medical School, opines on pending healthcare reforms.

A Rational Loss for Bill Belichick

noreply@blogger.com (Greg Mankiw) — Tue, 17 Nov 2009 14:38:00 +0000

Chapter 2 of my favorite textbook has a box on David Romer's work on 4th down strategies in football. One fan of this work is Patriots' coach Bill Belichick, who recently applied Romer's analysis. Click here to learn more.

It did not work out well in this particular case, and Belichick is coming under some heat for his call. This does not mean Romer and Belichick are wrong. Some strategies that fail ex post might be optimal ex ante. Randomness is a fact of life, even if Patriots' fans do not fully appreciate it.

The Actuary on the House Bill

noreply@blogger.com (Greg Mankiw) — Tue, 17 Nov 2009 07:54:00 +0000

Click on the graphic to enlarge.

Keith Hennessey summarizes the actuary's report on the House healthcare reform bill:

• The bill would mean almost 30 M new people in government-run insurance, more than four times as many as would be newly insured through private coverage.
• By far the largest effect of the bill would be to enroll more than 23 M new people in two existing government programs, Medicaid and S-CHIP. Medicaid is today widely regarded as fiscally unsustainable before adding more people.
• Foster estimates that 18 M people would remain uninsured and have to pay the penalty tax. These people are clearly worse off than they would be under current law.

News for New Econ PhDs

noreply@blogger.com (Greg Mankiw) — Mon, 16 Nov 2009 14:34:00 +0000

If you are an economics graduate student on the job market this year, click here. Everyone else: Never mind.

Supply, Demand, and Healthcare Reform

noreply@blogger.com (Greg Mankiw) — Sun, 15 Nov 2009 18:41:00 +0000

Let's review some basic principles of supply and demand: If a government policy increases the demand for a service, the price of that service tends to rise. If the government prevents prices from rising, shortages develop. The quantity provided is then determined by supply and not demand. In the presence of such excess demand, the result could be a two-tier market structure. Consumers who can somehow pay more than the government-mandated price will be able to purchase the service, while those paying the controlled price may be unable to find a willing supplier.

Those principles lie behind this story from the Washington Post:

A plan to slash more than $500 billion from future Medicare spending -- one of the biggest sources of funding for President Obama's proposed overhaul of the nation's health-care system -- would sharply reduce benefits for some senior citizens and could jeopardize access to care for millions of others, according to a government evaluation released Saturday.
The report, requested by House Republicans, found that Medicare cuts contained in the health package approved by the House on Nov. 7 are likely to prove so costly to hospitals and nursing homes that they could stop taking Medicare altogether.
Congress could intervene to avoid such an outcome, but "so doing would likely result in significantly smaller actual savings" than is currently projected, according to the analysis by the chief actuary for the agency that administers Medicare and Medicaid. That would wipe out a big chunk of the financing for the health-care reform package, which is projected to cost $1.05 trillion over the next decade.
More generally, the report questions whether the country's network of doctors and hospitals would be able to cope with the effects of a reform package expected to add more than 30 million people to the ranks of the insured, many of them through Medicaid, the public health program for the poor.
In the face of greatly increased demand for services, providers are likely to charge higher fees or take patients with better-paying private insurance over Medicaid recipients, "exacerbating existing access problems" in that program, according to the report from Richard S. Foster of the Centers for Medicare and Medicaid Services.
Though the report does not attempt to quantify that impact, Foster writes: "It is reasonable to expect that a significant portion of the increased demand for Medicaid would not be realized."

Netherlands joins the Pigou Club

noreply@blogger.com (Greg Mankiw) — Sat, 14 Nov 2009 16:45:00 +0000

A student alerts me to this story about the new Dutch policy to internalize externalities:

The Dutch government said Friday it wants to introduce a "green" road tax by the kilometre from 2012 aimed at cutting carbon dioxide emissions by 10 percent and halving congestion.
"Each vehicle will be equipped with a GPS device that tracks how many kilometres are driven and when and where. This data will be then be sent to a collection agency that will send out the bill," the transport ministry said in a statement.
Ownership and sales taxes, about a quarter of the cost of a new car, will be scrapped and replaced by the "price per kilometre" system aimed at cutting the Netherlands' carbon dioxide emissions by 10 percent.
"Traffic jams will be halved and it helps the environment," the ministry said.
Dutch motorists driving a standard family saloon will be charged 3 euro cents per kilometre (seven US cents per mile) in 2012. That would increase to 6.7 cents (16 US cents per mile) in 2018, according to the proposed law.

Bending the Curve: How's it going?

noreply@blogger.com (Greg Mankiw) — Fri, 13 Nov 2009 11:19:00 +0000

Jim Capretta has the answer.

Steuerle on Healthcare Reform

noreply@blogger.com (Greg Mankiw) — Thu, 12 Nov 2009 11:20:00 +0000

Gene Steuerle of the Urban Institute describes the maze of incentives embedded in the pending healthcare reform bill.

The Poverty Trap

noreply@blogger.com (Greg Mankiw) — Thu, 12 Nov 2009 01:58:00 +0000

Chapter 20 of my favorite textbook has a section on antipoverty programs and work incentives. One basic point is that when multiple income-based programs are piled on top on one another, the implicit marginal tax rate can reach or even exceed 100 percent.

The chart above (source, via Kling) illustrates this phenomenon. It shows income after taxes and transfers as a function of earned income. Notice that as earned income rises from about $15,000 to $30,000, income after taxes and transfers is roughly flat. Indeed, it could even fall. The bottom line: If you are poor, the government is inadvertently ensuring that you have little incentive to try to improve your condition.

Request to CBO: Can you please make and disseminate charts like the one above? Producing this kind of chart correctly is not easy (and I cannot fully vouch for the accuracy of this one) because a variety of different government programs are involved, and their rules are often complex. CBO has the staff to do it right. Moreover, if such a chart came from a high profile, widely respected, and nonpartisan source such as CBO, the problem would get more attention. It certainly deserves it.

I bet there are people in the Obama administration who are quietly worrying about this problem. Why do I say this? Read this old post. The story there is told by Jeff Liebman, a very smart Kennedy School professor now working for President Obama.

Update: Here is some related work by Larry Kotlikoff and David Rapson.

For Extra Practice

noreply@blogger.com (Greg Mankiw) — Wed, 11 Nov 2009 20:23:00 +0000

A student emailed me today looking for additional practice problems to help him prepare for tests in his introductory economics course. Where did I send him? To the Study Guide prepared by David Hakes to accompany my favorite textbook.

Old Time Recession

noreply@blogger.com (Greg Mankiw) — Wed, 11 Nov 2009 11:30:00 +0000

More on LHS

noreply@blogger.com (Greg Mankiw) — Tue, 10 Nov 2009 11:19:00 +0000

Vanity Fair profiles Larry Summers.

Dick Armey on Harvard Economics

noreply@blogger.com (Greg Mankiw) — Mon, 09 Nov 2009 16:42:00 +0000

Okay, this has got to be one of the goofiest comments from a major political figure in recent weeks:

"I don’t consider Larry Summers a serious economist," [Dick] Armey said. “You can get a Ph.D. from Harvard without ever having seriously considered the subject.” (Source).

If Dick Armey wants to criticize Larry Summers or the economic policy of the Obama administration, there is no shortage of ammunition and easy targets. But saying that Larry is not a serious economist, or that a PhD from one of world's preeminent economics departments doesn't mean much, makes Mr Armey look more than a tad ridiculous.

Unintended Consequences

noreply@blogger.com (Greg Mankiw) — Mon, 09 Nov 2009 15:06:00 +0000

A surprising effect of the minimum wage:

Growing consumption of increasingly less expensive food, and especially “fast food”, has been cited as a potential cause of increasing rate of obesity in the United States over the past several decades. Because the real minimum wage in the United States has declined by as much as half over 1968-2007 and because minimum wage labor is a major contributor to the cost of food away from home we hypothesized that changes in the minimum wage would be associated with changes in bodyweight over this period. To examine this, we use data from the Behavioral Risk Factor Surveillance System from 1984-2006 to test whether variation in the real minimum wage was associated with changes in body mass index (BMI).... We find that a $1 decrease in the real minimum wage was associated with a 0.06 increase in BMI.... Real minimum wage decreases can explain 10% of the change in BMI since 1970. We conclude that the declining real minimum wage rates has contributed to the increasing rate of overweight and obesity in the United States.

From David Meltzer and Zhuo Chen.

Feldstein on Obamacare

noreply@blogger.com (Greg Mankiw) — Mon, 09 Nov 2009 01:50:00 +0000

Marty's latest salvo.

Take Out Your Pencils

noreply@blogger.com (Greg Mankiw) — Sun, 08 Nov 2009 11:07:00 +0000

For those blog readers who fondly recall exams in introductory economics (I am sure there are many), here is a fun problem based on a question from a recent ec 10 test. Enjoy!

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.

Unemployment Update

noreply@blogger.com (Greg Mankiw) — Sun, 08 Nov 2009 10:15:00 +0000

Click on the graph to enlarge. Click here for my interpretation.

Spreading the Word

noreply@blogger.com (Greg Mankiw) — Sat, 07 Nov 2009 13:53:00 +0000

My favorite introductory economics textbook comes in many variants. For American students, there are five versions, each with a different subset of chapters, so every instructor can find one that best suits his or her course. Students abroad can use one of these or choose among various editions that have been tailored to particular regional institutions and languages. Yesterday, I learned about two new members of the line-up: the French Canadian editions, available for both micro and macro.

Environmentalism vs Homeownership

noreply@blogger.com (Greg Mankiw) — Thu, 05 Nov 2009 13:01:00 +0000

My Harvard colleague Ed Glaeser looks at the negative externalities from suburban sprawl.

Assuming a Can Opener

noreply@blogger.com (Greg Mankiw) — Wed, 04 Nov 2009 09:39:00 +0000

I have previously expressed skepticism about projected Medicare spending assumed in the health reform effort making its way through Congress. If reductions in spending don't materialize as Congress now posits, health reform will not turn out to be deficit neutral but will, instead, add to the large fiscal gap we are bequeathing to future generations. In a recent letter, CBO gives some numbers about projected Medicare spending that shows how wildly unrealistic it is:

The bill would put into effect (or leave in effect) a number of procedures that might be difficult to maintain over a long period of time. It would leave in place the 21 percent reduction in the payment rates for physicians currently scheduled for 2010. At the same time, the bill includes a number of provisions that would constrain payment rates for other providers of Medicare services. In particular, increases in payment rates for many providers would be held below the rate of inflation (in expectation of ongoing productivity improvements in the delivery of health care). Based on the extrapolation described above, CBO expects that Medicare spending under the bill would increase at an average annual rate of roughly 6 percent during the next two decades—well below the roughly 8 percent annual growth rate of the past two decades, despite a growing number of Medicare beneficiaries as the baby-boom generation retires.

Thanks to the blog reader who drew this passage to my attention.