WSJ: In the 1960s the future of aviation seemed bright. In 1958 Boeing had built its first jetliner, the 707, which cruised at speeds of up to 600 mph. The Concorde came along in 1969, flying at Mach 2—more than 1,500 mph. An age of affordable supersonic flight seemed inevitable, promising U.S. coast-to-coast travel in just 90 minutes. Today, neither the Concorde nor any other supersonic passenger jet operates. And the 707, still in limited use, remains one of the fastest commercial jets operating in the world. What happened? Regulation happened. In 1973, shortly after Boeing abandoned the 2707, its Mach 3 government-funded competitor to the British- and French-made Concorde, the Federal Aviation Administration issued a rule banning supersonic transport over the U.S.

And why did we ban supersonic transport? It seems almost like a joke–because we were worried about noise. What would Chuck Yeager say? (He’s still alive and re-enacted his 1947 supersonic flight in 2012 at the age of 89).

Moreover, the noise scare was overblown. Incredibly, it was only after the FAA banned supersonic transport over the US that a careful study was done at Heathrow airport and that study found that the Concorde taking off and landing was only modestly louder than a regular jet. Moreover, as the study reported:

Whenever there was a Concorde departure from Heathrow, subsonic jets recorded a higher or equal noise level at the relevant fixed monitoring sites on 2 days out of 3.

The technology to produce quieter supersonic aircraft exists today but we won’t see really big investment in the industry until the outright ban on supersonic aircraft is lifted. As Dourado and Hammond write:

If the original ban was an overreaction, today it’s an outright absurdity—and remains in place due more to regulatory inertia and the FAA’s deeply precautionary culture than a sober accounting of costs and benefits.

I suspect that we will eventually lift the ban and get quieter and faster supersonic aircraft. But when we do so don’t make the mistake of thinking that it was wise to wait. As I pointed out in my earlier piece on Uber of the Sky, technological development is endogenous. If you ban supersonic aircraft, the money, experience and learning by doing needed to develop quieter supersonic aircraft won’t exist. A ban will make technological developments in the industry much slower and dependent upon exogeneous progress in other industries.

When we ban a new technology we have to think not just about the costs and benefits of a ban today but about the costs and benefits on the entire glide path of the technology.