This seems like a hasty conclusion to make. There are plenty of things that correlate with the stagnation of economic growth. I'm aware the author goes on to say almost the same thing after making this statement, but it is clear the author is trying to offer the ban on supersonic flight over soil to be the cause of economic stagnation in America.

To borrow a term from Ross Douthat, there is something decadent about putting a complete halt to the development of a key technology simply because a few otherwise harmless sonic booms might annoy a vocal minority.

I fail to see how there has been a complete halt on the development of supersonic technology. A ban on supersonic flight over US soil is not a ban on the development of the technology.

We need to get back to doing great things.

Who says we aren't?

If we want growth—if we want greatness—it’s time to make America boom again.

I can't agree with the author's conclusion. Besides, they don't really make an effort in their article to tie the development of supersonic flight over land to economic growth. This is more of a "build it and they will come" conclusion. I don't buy it.