In this case, the US decline probably started in the 1970s when they left the gold standard.
https://upload.wikimedia.org/wikipedia/commons/3/3a/Federal_...
Looks like 1st percentile wage growth stagnated right around 1970, but 99th percentile wage growth didn't start accelerating until around 1980 - right around when bond prices started rising again, after falling through the 70s. And they've been rising ever since.
Or are only only referring to incarceration rates?