There is so much about papers like this that make me skeptical. 1) It assumes we've been good at measuring growth. Which to me is dubious. Our current system c

There is so much about papers like this that make me skeptical. 1) It assumes we've been good at measuring growth. Which to me is dubious. Our current system counts the production, deployment and detonation of a bomb all as positive production meanwhile not counting unpaid domestic work. I know economists don't like to out a value to different types of services and goods because they feel they are putting a finger on the scale. But they are doing just as much by using a blind metric which ends up counting some work and not other. 2) It never cost adjusts growth. For example, all that wonderful growth in the midst of the 20th cwntury incurred significant externalities. The system we have now tries much harder to make producers realize their externalities. This curbs growth which is not necessarily a bad thing. 3) It assumes we can atomize historic growth and single out what things contributes to what. But this seems ridiculous especially how these factors interact and are not necessarily seperable. For example, we happen to live in a universe in which the movement of electrons can be used transmit energy and appropriate it to many tasks. The story of the 20th cwntury's economy is very much the story of how we mastered this one property of nature. Electrification doesn't just provide heat and light. It enables the transportation of water. It enables the construction of more and larger structures. It enables the creation of aluminum and plated metals. Aluminum itself allows many features of our world we take for granted. From airplanes to electronics. But does abundant aluminum lay at the feet of scientific innovations? In its infancy for sure but after some basic science it is widespread cheap electrification which allows us to mass produce aluminum. How much of that economy do we count to cutting edge science? It's not easily disentangled from popular politics which allowed the mass construction of hydroelectric damns throughout the U.S. and other countries. There is a possible future in which for centuries, growth has slowed to something more than Renaissance levels but well below mid 20th century levels. In such a future we might look back at this period as the time we mastered the single most useful physical property of our universe and so of course it was an era of unprecedented growth. I'm not saying they're wrong. But every time someone from Bill Gates to NBER talks about this issue of growth, whether it has slowed, why it as slowed, how it can be increased, I just get this feeling that people are failing to realized what a unique time we live in. How unique the 150 years preceding it really are. And how little we know about why it happened.