Thursday, March 14, 2019

Greg Mankiw on Textbooks, and Some Reactions

Greg Mankiw is the author of two leading undergraduate economics textbooks: one for the introductory principles of economics course and the other for intermediate macro. At his blog, he linked an essay he has just written, "Reflections of a Textbook Author" (March 6, 2019).  Those teaching or taking either principles or intermediate macro will find it of interest, as well as those who have contemplated writing a textbook of their own.

I've had experiences to build up some views about intro economics pedagogy over the years. I've been involved in several introductory textbooks: first as a commenter and editor for the first edition of the introductory Economics textbook by Joseph Stiglitz published in 1993, and more recently as the authors of my own Principles of Economics textbook (first edition published in 2008, and of course I commend the most recent high-quality and affordable edition to your attention), which was used in a  revised, shortened, and reorganized form as the backbone for the freely downloadable Principles of Economics book available through OpenStax. I've taught intro econ at Stanford and the University of Minnesota. I've also done some non-textbook, non-classroom introductions to economics. For example, back in the mid-1990s I recorded the first edition of an Economics course, explaining terminology and trends without graphs, for the Teaching Company back in 1995--the most recent edition is here. Those lectures became the basis for my 2012 book The Instant Economist. Last year, I did a series of 90 podcasts, 15 minutes each, for the Chinese company Ximalaya, explaining intro economics terms in a nontechnical way with examples and context from China's economy.

Here, I'll pass along a few thoughts from Mankiw's essay that caught my eye, with some reactions of my own, but Greg is a lovely and insightful writer, so there's lots more at the essay itself.

Principles Instructor as Ambassador
"Just as ambassadors are supposed to faithfully represent the perspective of their nations, the instructor in an introductory course (and intermediate courses as well) should faithfully represent the views shared by the majority of professional economists. ... This perspective of instructor as ambassador raises the question of what instructors should do if they hold views far from the mainstream of the economics profession. If you are an Austrian or Marxist economist, for example, what should you do if asked to teach an introductory course? In my view, there are only two responsible courses of action. One is to sublimate your own views and spend most of the course teaching what the mainstream believes, even if you disagree with it. Because many introductory students will take only one or two courses in economics throughout their educations, it would be pedagogical malpractice, in my judgment, to focus on an idiosyncratic minority viewpoint. The other responsible course of action is to avoid teaching introductory (and even intermediate) courses entirely." 
I very much agree with this sentiment. But I'd also add that there should be some room, at least at larger universities, for some nonstandard overviews of economics. For example, many schools have  freshman seminars taught by regular faculty that focus on writing, but with content specific to the professor. Or departments could offer some intro-level courses, without prerequisites, that aren't the standard course. One would probably need to specify that these alternative courses would not be a good preparation for intermediate micro and intermediate macro to follow. But carving out and preserving some room for experimentation at the intro level seems potentially useful.

From Supply and Demand to Consumer and Producer Surplus
"Haven’t supply and demand always been at the center of the introductory course? Surprisingly, no. The first edition of Paul Samuelson's great text, published in 1948 and 608 pages long, did not introduce supply and demand curves until page 447. That is in part because Samuelson, writing in the shadow of the Great Depression, began his book by emphasizing Keynesian macroeconomics. As the book was revised over many editions, standard microeconomic tools became more prominent. But even today, many introductory courses do not develop the framework of supply and demand as fully as they should. In particular, welfare economics is sometimes not given sufficient coverage. The basic tools of welfare economics are consumer surplus and producer surplus, which are natural extensions of supply and demand."
Pretty much all modern intro textbooks are the intellectual children of Samuelson's 1948 text, just revised and updated in various ways. My understanding is that if you go back before that textbook, it was common for intro economics courses to have almost no graphs at all--whether supply-and-demand or otherwise. Following Samuelson, it was also standard to do macro before micro, which seemed based on the assumption that macro had more of a connection to current events and would be an easier way to hook intro students into the subject.

I confess that I'm more dubious than Mankiw when it comes to bringing consumer and producer surplus into the intro class. In my experience, triangular areas under curves are hard for a lot of intro students, and I'm not sure the payoff is very high for the intro student--which is most of them--who aren't ever going to take another econ class. In the great struggle over what to include and what to leave out, I'd put less emphasis on on this topic than Mankiw--and I wouldn't quarrel with an instructor who decided just to leave it out.

Including Too Much?
"For many years, Otto Eckstein ran the introductory course at Harvard. Unfortunately, I never met him as he passed away just before I joined the faculty. But I have heard one of his aphorisms. Apparently, Otto often told section leaders, `The less you teach them, the more they learn.' What I believe he meant by this is that instructors should avoid overwhelming introductory students with too much information all at once. ... As economists, we teach our students about scarcity. As instructors and textbook authors, we should remember that student time is a scarce resource. We must avoid making our courses encyclopedic. That means taking out all of the easily ignored details and stressing the big ideas. The main goal of the introductory course is not to produce future economists but to produce well-informed citizens. Any topic that a person does not need to understand to intelligently follow the news is a plausible candidate for omission. One risk when simplifying matters for students is oversimplification, losing too much of the nuance that economists bring to an issue. But given the difficulty some students have learning basic economics, it is a bigger risk to overcomplicate the analysis early in the course."
In writing a book, there are ongoing pressures to add more. Every reader has a pet topic, or a pet example, or a pet caveat, that would only take another page. A standard response is to write a textbook with the idea that certain chapters will be "core," while other instructors can be dropped by professors if they prefer. In my own textbook, for example, there is a chapter on imperfect information and insurance, and another chapter on financial markets, which can be dropped. In one of the macro chapters, I include the Keynesian cross diagram for teaching about macro in the short-run, but I place it as the second half of a chapter so that it can be smoothly omitted if a professor desires.

While the individual choices about what to include are usually defensible, it  seems fair to me to ask whether the current intro model--whether Mankiw's book or my own--is actually aimed at producing well-informed citizens rather than prepping students for the intermediate micro and macro courses that typically follow in the undergrad econ major. As someone who took intro econ awhile back about their memory of the course, and you're likely to get a wry smile and a memory of how there were a bunch of graphical exercises to solve. It's not obvious to me that someone who has taken the standard intro class would have been in a substantially improved position "to intelligently follow the news" about, say, the causes of the Great Recession, or what happens when the policy interest rate targetted by the Federal Reserve went to near-zero, or the arguments about the Patient Protection and Affordable Care Act and the Dodd-Frank bill passed in 2010, or the current arguments over China's economic growth or the Tax Cuts and Jobs Act passed in 2017. It's not clear to me that the standard intro class empowers students to know where and how to look up data and mainstream argument on these subjects and others, either.

Everyone has worried for a long time about the intro course including too much, but at the end of the day, we keep ramming stuff into it.  I'm not sure the current balance is right.

Free textbooks?
"One possibility is to have the fixed costs of production paid by a foundation grant (I am looking at you, Bill Gates) and then make the digital book freely available. This is similar to the common suggestion that newspapers like The New York Times should move from for-profit to non-profit status and then be supported by charitable donors, much like National Public Radio. Yet I am skeptical that this reform would improve on the status quo of the textbook market. After all, the current for-profit educational publishers are not that profitable, and there is no reason to think that a non-profit entity would find cost savings that have eluded existing publishers. I am afraid that the only way to substantially cut costs would be to reduce quality, which would not be in the students’ interests."
OpenStax is an organization that makes digital books freely available for a wide range of college courses, including the Economics book in which I played a role. It is indeed  partly funded by the Gates Foundation.  Mankiw suggests that "free" books may have an undesirable quality tradeoff.

Quality is often in the eye (and the wallet) of the beholder. But the idea behind OpenStax is that a lot of intro books across a lot of subjects are pretty similar: say, think about the likely similarities between intro textbooks in algebra, statistics, accounting, chemistry, and physics.  If instructors for intro econ should be ambassadors representing the common wisdom, books which do this will have a lot of overlap, too. Personally, I prefer my textbook from Textbook Media to the revised, reworked, reorganized, and shortened version that became the OpenStax book. But other instructors may disagree, or may just feel that "free" is worth it.

The bigger quality tradeoff with free books is about the ancillary materials that accompany a book: banks of multiple choice questions that can be organized into quizzes and tests, with machine-scoring; problem sets; slides and videos for the classroom; animated graphics; text-to-audio for those who learn better by listening; structured economic markets and exercises that can be "played" by students, and then mined for underlying lessons; and more. Some ancillaries have been created for the OpenStax free books, but for-profit publishers invest a lot into these ancillaries, and into making sure they function together in a coordinated way. I suspect that that the quality tradeoffs between free and priced textbooks are mild, compared to the quality tradeoffs between ancillary materials for the books.

How Much Do You Like the Act of Writing and Revising?
"If you are thinking about writing a textbook, the most important question to ask yourself is: Do you enjoy the process of writing and revising (and revising and revising and…)? Not just tolerate it, but really enjoy it? ... I actually enjoy the triennial revisions of my textbooks, not only because they allow me to update my texts for the ever-changing world but also because they give me the chance to go through the manuscript and tinker some more. I can change `the curve is upward sloping' to “`he curve slopes upward,' saving one word and two syllables! If that edit does not strike you as a life-affirming victory, you are not a writer at heart."
This comment reminded me of a couple of others. One was from an economist friend of mine who had serious talks with a publisher about writing a textbook and walked right up to the edge of a sizeable advance payment--before deciding not to go through with it. He told me that in looking the reality of a textbook project in the face: "I discovered that there's a big difference between wanting to write a book and wanting to have written a book."

The other is to emphasize that for most of us, good expository writing involves a lot of rewriting. When someone says that the explanations in my textbook are smooth and fluent and easy-to-follow, I always think: "Well, after about the 6th or 10th revision, it became a lot more clear." I remember the advice of "John Kenneth Galbraith on Writing, Inspiration, and Simplicity" (August 25, 2015). Galbraith, who was one of the truly fine prose stylists in economics, wrote: 
"The best place to write is by yourself, because writing becomes an escape from the terrible boredom of your own personality. It's the reason that for years I've favored Switzerland, where I look at the telephone and yearn to hear it ring. ... There may be inspired writers for whom the first draft is just right. But anyone who is not certifiably a Milton had better assume that the first draft is a very primitive thing. The reason is simple: Writing is difficult work. Ralph Paine, who managed Fortune in my time, used to say that anyone who said writing was easy was either a bad writer or an unregenerate liar. Thinking, as Voltaire avowed, is also a very tedious thing which men—or women—will do anything to avoid. So all first drafts are deeply flawed by the need to combine composition with thought. Each later draft is less demanding in this regard. Hence the writing can be better."