Persistence can be a trite subject. So it's extremely difficult to write poignantly about the matter. But I'll give it a try and we'll see what happens.
I'm very confused about how to define persistence - there seems to be a consensus that it's good, but no one seems to offer a valid definition. It's challenging for me to differentiate between persistence and stubbornness, persistence and hope, persistence and luck. Whether in sports, social matters, or business, the line between unwise resistance and brave fortitude is usually very thin.
This is why I have difficulty in applying the lessons of Seth Godin's famous book, The Dip. How do we know when the boundary has been crossed? How do we know when a particular fight is not worth fighting? It's hard to tell without the right definition.
Any quantitative approach is in the end based on various assumptions - which are at best reasonable guesses. Competing studies place their respective bets on either snap-decisions or prolonged contemplation. It's frustrating to realize that there is no absolute answer.
So my best guess at the moment is that persistence is actually some functional combination of stubbornness, hope, and luck. As a wise friend keeps saying, maybe the solution stems from answering why instead of how.