On the use of math in economics (version 2.0)…

In response to my previous posting entitled “On the use of math in economics…”, my colleague Allen Seward pointed out the following quote to me (Attributed to Alfred Marshall; see Todd G. Buchholz, 1989, New Ideas from Dead Economists, New York: Penguin Group, p. 151.):

In a letter to his protégée, A.C. Pigou, he [Marshall] laid out the following system: “(1) Use mathematics as shorthand language, rather than as an engine of inquiry. (2) Keep to them till you have done. (3) Translate into English. (4) Then illustrate by examples that are important in real life (5) Burn the mathematics. (6) If you can’t succeed in 4, burn 3. This I do often.”

On the use of math in economics…

As I prepare my course in managerial economics, I have tried to put myself in my students’ shoes and ask why all the math?  This is a particularly relevant question because my students are enrolled in Baylor’s executive MBA program, and they (quite understandably) have no interest in becoming professional economists. 

In his recent blog entry entitled “Mathematics and Economics”, Paul Krugman notes, among other things, that “Math in economics can be extremely useful”, and that math can serve an essential analytic function by helping to clarify one’s thoughts.  Some other samplings from the economics blogosphere include the following observations:

  1. Greg Mankiw (cf. http://gregmankiw.blogspot.com/2006/09/why-aspiring-economists-need-math.html) notes, among other things, that “Math is good training for the mind. It makes you a more rigorous thinker.”
  2. Jason DeBacker (cf. http://www.econosseur.com/2009/02/why-economists-use-so-much-math.html) makes the following observations: “Math provides a common language for economic thought”, and “Math helps to quantify tradeoffs.”  He also notes that “Using math puts in plain sight the assumptions that lie behind a model and the mechanisms at work in the model”, which is consistent with Professor Krugman’s observation noted above.

However, I am also reminded of the famous quote “it is better to be vaguely right than precisely wrong” which is commonly (and incorrectly) attributed to the famous economist John Maynard Keynes. (For what it’s worth, O’Donnell (2006) notes (see p. 403, footnote 14) that “This saying so aptly captures a strand in Keynes’s thought that he is frequently, but wrongly, treated as its author”; apparently, the original source for this memorable quote was a contemporary of Keynes by the name of Wildon Carr (see Shove (1942: 323)). 

References

O’Donnell, R., 2006, “Keynes’s Principles of Writing (Innovative) Economics,” Economic Record 82 (259), 396-407.

Shove, G.F. (1942), “The Place of Marshall’s Principles in the Development of Economic Theory,” Economic Journal, 52 (208), 294–329.

Assorted Links (9/18/2009)

Here’s a list of articles that I have been reading today (organized by topic):

Global Warming

Wall Street Journal: “A carbon strategy the world can afford.”

Health Care Reform

  • Congress Veers Left on Health Care, by Kim Strassel
  • Obama, Too Subtle to Lie, Misleads on Health Reform, by Charles Krauthammer

Washington Post: “You lie? No. Barack Obama doesn’t lie. He’s too subtle for that. He . . . well, you judge.”

Wall Street Journal: “Why an individual mandate could be struck down by the courts.”

Politics

New York Times : “The backlash against President Obama is the latest iteration of a populist tendency against money being siphoned off by condescending elites and going to those who do not work.”

Assorted Links (9/17/2009)

Here’s a list of articles that I have been reading today (organized by topic):

Behavioral Economics

Energy

Wall Street Journal: “We’re about to destroy the environment in the name of saving it.”

Financial Crisis

  • The Stimulus Didn’t Work, by John Cogan, John Taylor and Volker Wieland

Wall Street Journal: “The data show government transfers and rebates have not increased consumption at all.”

Health Care Reform

Religion

  • The Right Way to Pray?, by Zev Chafets

New York Times: “Americans aren’t sure they know how to talk to God. Fortunately, there is plenty of instruction available.”

    Science

    • Are Your Friends Making You Fat?, by Clive Thompson

    New York Times: “Nicholas Christakis and James Fowler say your friends — and even your friends’ friends — can make you quit smoking, eat too much or get happy. A look inside the emerging science of social contagion.”

    Assorted Links (9/16/2009)

    Here’s a list of articles that I have been reading today (organized by topic):

    Economics and the Financial Crisis

    Wall Street Journal: “The time to worry about moral hazard is now.”

    Health Care Reform

    • Mandated Health Insurance Squeezes Those in the Middle, by Vanessa Fuhrmans

    Wall Street Journal: “President Barack Obama and his congressional allies have made insuring nearly all Americans a major goal of overhauling the nation’s health-care system. One of their toughest challenges will be trying to cover people like Ron Norton of Worcester, Mass.  Mr. Norton, 49 years old, is an adjunct professor at a local community college who earns about $40,000 a year. He’s also one of roughly 200,000 Massachusetts residents who remain uninsured despite a state law requiring residents to have health insurance. “I can’t use up all of my savings just to buy mandatory insurance,” Mr. Norton says. It’s like penalizing “the homeless for refusing to buy a mansion.”

    • Some Firms Are Already Bending Stubborn Health Care Cost Curve, by Roy Ramthun and Merrill Matthews

    Investors Business Daily: “President Obama repeatedly says of health care changes that doing nothing would be worse than an overhaul. But exactly why is that? The fact is that health insurance is slowly reforming itself, largely in response to employer and consumer demand.”

    • Another Health-Care Invention

    Wall Street Journal: “Obama and the cost of individual insurance.”

    Sociology of Religion

    • Fight Nights and Reggae Pack Brazilian Churches, by Alexei Barrionuevo

    New York Times: “A growing evangelical movement in Brazil is attracting young people by adopting their culture.” 

    Statistics

    • Seeking Accurate Job-Creation Numbers, by Carl Bialik

      Assorted Links (9/15/2009)

      Here’s a list of articles that I have been reading today (organized by topic):

      Catastrophes

      • One year after Hurricane Ike, from the Boston Globe’s “Big Picture” blogsite

      Boston Globe: “One year after Hurricane Ike tore across the gulf coast of Texas, residents paused on Sunday to observe the anniversary of the costliest natural disaster in Texas history. Destroying or damaging many thousands of houses, including 3/4 of all homes in Galveston, Ike’s 110 mph winds caused more than $29 billion in damage, and took the lives of at least 72 in the United States. In Galveston one year later, 75% of businesses have reopened, much of the debris has been cleared, and 95% of the population has returned, but much work still remains to be done as residents continue to rebuild and recover. Collected here are a series of before-and-after photographs – which (starting with the second one below) will fade between “before” and “after” when clicked. (13 photo pairs total)”

      Economics

      Donald Marron notes that the student loan crises of 2006–2007 and 2008 “…had the same root cause: the fact that the government, rather than market forces, determined how much lenders were paid for making guaranteed student loans. In both cases, the government got the payment levels wrong, and the crises followed soon thereafter.”

      Financial Crisis

      • Lehman and the Financial Crisis, by John Cochrane and Luigi Zingales

      Wall Street Journal: “The lesson is that institutions that take trading risks must be allowed to fail.”

      Game Theory

      • Game theory links 9-15-09, by Presh Talwalkar

      Foreign Policy

      Wall Street Journal: “President Obama can’t outsource matters of war and peace to another state.”

      Health Care Reform

      • Government Medicine vs. the Elderly, by Rupert Darwall

      Wall Street Journal: “In Britain in 2007-08, 16.5% of deaths came after ‘terminal sedation.’”

      Assorted Links (9/14/2009)

      Here’s a list of articles that I have been reading today (organized by topic):

      Economics and the Financial Crisis

      Here, Alex Tabarrok critiques Paul Krugman’s recent New York Times essay entitled “How Did Economists Get It So Wrong”; Krugman’s answer to his own question is that the economics profession had become so fixated on so-called efficient markets theory that “Discussion of investor irrationality, of bubbles, of destructive speculation had virtually disappeared from academic discourse.” Tabarrok counters that “…if we are to understand recent history it’s neither true nor useful to argue that Greenspan and other economists thought the price was always right”.

      Health Care Reform

      • Fact-Checking the President on Health Insurance, by Scott Harrington

      Wall Street Journal : “Responsible reform requires careful analysis of the underlying causes of problems in health insurance and informed debate over the benefits and costs of targeted remedies. The president’s continued demonization of private health insurance in pursuit of his broad agenda of government expansion is inconsistent with that objective.”

      Politics, Law and Regulation

      • Free Speech, Now that Speech Is Free, by Gordon Crovitz

      Wall Street Journal: “Political campaign regulations are silly in the age of YouTube.”

      Assorted Links (9/13/2009)

      Here’s a list of articles that I have been reading today (organized by topic):

      Economics and the Financial Crisis

      • Talking Business: Lehman Had to Die So Global Finance Could Live, by Joe Nocera

      New York Times: “The Lehman Brothers failure caused a panic that spurred Congress to approve the $700 billion bailout.”

      New York Times: “In the aftermath of the financial crisis, many experts want formulas for risk that look at human behavior and how it can change rapidly.”

      Health Care Reform

      New York Times: “Hopes for a public insurance program are faltering in the face of opposition from the insurance and health care industries and conflicting signals from the White House.”

      Science

      • Is Happiness Catching?, by Clive Thompson

      New York Times: “Nicholas Christakis and James Fowler say your friends — and even your friends’ friends — can make you quit smoking, eat too much or get happy. A look inside the emerging science of social contagion.”

      Assorted Links (9/12/2009)

      Here’s a list of articles that I have been reading today (organized by topic):

      Economics and the Financial Crisis

      University of Chicago economics professor Casey Mulligan calculates that the cost per job year for the jobs that the Obama administration claims have been “saved” as a result of last January’s stimulus package comes to $1.2 million, and that through June of 2009, we had spent $100 billion to supposedly raise GDP (according to the Obama administration’s own estimates) a mere $20.3 billion.

      Health Care Reform

      Investors Business Daily : “The day after President Obama’s impassioned speech for big-government health care, Wall Street bet heavily that the so-called government-insurance option he supports is dead.” 

      9/11

      • Remembering September 11th, from the Boston Globe’s “Big Picture” blogsite

      Assorted Links (9/11/2009)

      Here’s a list of articles that I have been reading today (organized by topic):

      Economics and the Financial Crisis

      • The Keynesians Were Wrong Again, by Peter Ferrara

      Wall Street Journal: “We won’t see a return to growth without incentives for job-creating investment.”

      Professor Mulligan points to Chicago colleague John Cochrane’s essay entitled “How did Paul Krugman get it so Wrong“, written in response to Paul Krugman’s essay “How did Economists get it so wrong?”

      Health Care Reform

      • Medicare Is No Model for Health Reform, by Grace-Marie Turner and Joseph R. Antos

      Wall Street Journal: “Many doctors refuse Medicare patients because payments are so low.”

      • The President’s Tort Two-Step, by Kim Strassel

      Kim Strassel’s essay explains, among other things, why the real “low hanging fruit” for reducing health care costs (via tort reform so as to mitigate its effect on the practice of so-called “defensive medicine”) is not likely to get picked; unfortunately, the plaintiff’s bar is far too powerful of a special interest in the current health care reform debate.

      9/11

      • The Children of 9/11 Grow Up, by Peggy Noonan

      Wall Street Journal: “College students talk about how the attack shaped their lives.”

      Wall Street Journal: “It was the furies of the Arab world, not Afghanistan, that struck America eight years ago today.”