Ignoring the difficult task of actually deciding when a civilization starts and stops, is there some theory that suggests that duration is the right measure? D

Ignoring the difficult task of actually deciding when a civilization starts and stops, is there some theory that suggests that duration is the right measure? Don't we need a reasonable model of how civilizations work. It would be interesting to incorporate and merge the data from Joseph Tainter's Collapse of Complex Societies with the data presented here.