I'm now wondering how you measure the ascendancy/decline of a civilization. I would offer a few measures off the top of my head. Anyone else got any suggestions?
1. Standard of living of the middle class in absolute terms (not relative to other classes or nations).
2. Standard of living of the poorest 5% in absolute terms (not relative to other classes or nations).
3. Maybe it's part of 1 and 2, but the cost and reliability of infrastructure - transportation, communication, sanitation, energy, etc.
4. Discovery - Is the civilization finding new resources to exploit, whether it's technology or land or something else?
5. Art and creativity - is there a sustained tolerance and appreciation of creativity?
6. Morale - are people optimistic about the future and wanting to contribute to it?
7. Life span - Maybe it's part of 1 and 2, but are people living long and healthy lives?
My ancestors fought cave bears so I could make this post.