I don't think this means very much. First of all, the entire EPR decline for men is concentrated in the post-1973 period - coincidentally just as macro policy started changing to provide less support for employment. So the EPR for prime-age men has been falling for 35 years, not 50. And those 35 years have also seen a long-term deterioration in wages, which can be an indicator of labor-market slack.
You cite the EPR for women as a counterexample. But that's an even worse labor-market indicator: It's been *rising* for 50 years. For example, the EPR for prime-age women was more than 10 points *higher* at the trough of the 1982 recession than at the 1969 peak of the late-sixties boom. Are you saying the labor market was stronger in 1982 than in 1969? At least looking at prime-age men strips out changes in gender norms about working, since the expectation that men should work is (presumably) just as strong now as it was 40 years ago.
But let's say you don't buy that. Let's say all E/Pop ratios are unreliable labor-market indicators for making long-run comparisons because it's impossible to strip out cultural or social developments that cause participation rates to change. But if that's true then the unemployment rate is also meaningless (which is how this thread started, with your post on Roubini's 9% call and 1982 vs. 2009). Unemployment rates depend on labor-force participation rates, but if those have been shifting around over the long run for poorly understood reasons then the U rate is useless too.
The chances are fairly strong that this recession will be worse than 1980/1982. Which would make it the worst since the GD.
SA