Real Engineering

Unless they can come up to engineering standards, economists should sell wisdom, not social engineering.

Through the miracle of the internet, I’ve been watching several series of lectures by Stephen Ressler, a retired professor of engineering at the U.S. Military Academy. You can get them from the Teaching Company in their Great Courses. Ressler’s lectures are great. The series on Greek and Roman architecture, for example, tells with wisdom and humor and utterly lucid exposition in 24 lectures how amazing, and underappreciated, were the ancients at building. Ressler connects the roads, buildings, bridges, aqueducts, and the rest to the basic science involved. He does similar lessons in applied science in his series of lectures on Engineering Failures and the Lessons, such as Boeing’s 737 MAX airplane. One of Ressler’s wise themes is that science by itself can mislead the engineers, especially when they are trying out novelties. What’s needed is not more mathematics, often, but experimenting at a small scale and consulting a deep knowledge of what has worked in practice. The Failures didn’t do it.

 Economists and politicians have over the past couple of centuries been telling us with increasing confidence that they can succeed at “social engineering” and applied science “like physicists do.” But they don’t know anything about what actually goes into physics or engineering. Their practice seldom reaches the standard of care that physical engineers employ. I mean, “never.” 

The economist George DeMartino writes about the “never” in two brilliant books, The Economist’s Oath: On the Need for and Content of Professional Economic Ethics [2011] and The Tragic Science: How Economists Cause Harm (even as they aspire to do good) [2022]. The engineers, DeMartino points out, have an elaborate ethical code, about all the details of construction—design, choice of materials, building, testing, and retesting. Economists don’t.

True, the economists who advise the government or private firms are more concrete and practical than the academic economists. An article by a professor of game theory or international economics, for example, exhibits a lovely mathematical model, derives hypothetical results, and then claims the “policy relevance” of the mathematics. It’s like the engineers since the early 19^th century, as Ressler explains, who have in many cases of failure let their mathematical models override their historical experience, or even their common sense. 

I said that the economists advising on real-world policies do better. But even at my beloved Cato Institute, where we take our advice to government very seriously indeed, and do not merely speculate, we should be doing more quantitative calculations and more historical inquiry, as the engineers do. When an engineer is thinking about the stresses of weight or weather on a beam in a bridge she asks persistently what the magnitude of the forces of compression, tension, and twist are, and asks whether they would cause the building or bridge to fail.

Unless they can come up to engineering standards, economists should sell wisdom, not social engineering.

Weekly column in Folha de São Paulo, Brazil
Translated into Portuguese for the newspaper.