On Jeffrey Sachs

A student emails me a query about my erstwhile colleague Jeffrey Sachs:

Professor Mankiw,

I have been debating with a friend of mine (we are both graduate students in economics) about Jeff Sachs. To me he seems to ignore the power of incentives--an unforgivable error for an economist. The article you recommended on your website shows this lamentable trait. Sachs blames Africa's problems chiefly on "the lack of aid promised 36 years ago and repeatedly since by rich nations." That isn't the real problem is it? Perhaps you would comment on Sachs' ideas on your blog.

[name withheld]

P. S. Like many others, I have high praise for your textbooks, from which I have profited greatly.

Development is not my field of specialty, but I do follow the debate from afar. Here is my take, as an outsider.

I have long admired Jeff for his energy and idealism. I believe that he is truly working hard to make the world a better place for the least fortunate among us.

Nonetheless, I often find myself skeptical about Jeff's prescriptions and the confidence he places in their success. The article on Jeff I cited yesterday in a previous post said:

Jeffrey Sachs is at once a scientist and a preacher in the field of economics.

As a description of Jeff's career, that sounds about right. Jeff delivers his policy advice with so much zeal that I am frequently knocked off my feet, as if I were listening to a particularly forceful fire-and-brimstone sermon.

But consider: Are these two roles compatible? Don't scientists and preachers have very different approaches to life? Scientists understand that much knowledge is tentative; they are always open to doubt. Preachers take much on faith; they approach the world with certitude. When I hear Jeff talk, I hear more preacher than scientist, and that makes me apprehensive. Unlike Harry Truman, I like two-handed economists. I don't often hear Jeff start a sentence "On the other hand,...."

I am sympathetic to Bill Easterly's critique of Jeff's work. Bill's approach has a compelling humility and eclecticism. In light of how little we know about economic development and how divided the economics profession is on the key issues, I am suspect of those who are extraordinarily confident in their views, as Jeff is. I wonder if Jeff is on the wrong side of the rhetorical Laffer curve: If he pushed his opinions less forcefully, he might be more persuasive.

Finally, I cannot help but mention Jeff's greatest asset: his wife, Sonia Ehrlich. Sonia is a doctor, and for many years she was my children's pediatrician. In that capacity, I got to know her fairly well, and I can attest that she is one of the most wonderful people I have ever met. The best thing I can say about Jeff is that he had the good sense to marry Sonia.