Then we'd be able to tell from the S&P 500 study if there were parity between the number of male and female CEOs.

But there aren't. There are way more men. About 9:1.

So it's very hard to tell what is going on.

For example, if there are roughly equal numbers of men and women with the same intrinsic competency, but people's instincts are, "Oh, huh, CEO, that's a job for a guy," unless the woman is really exceptional, then the equivalent quality comparison would be all the women against the best 1/9th of guys (not most profitable, but "best" as in "oh, wow, I want him running my company, he's great!").

Alternatively, companies that hire female CEOs may value diversity more overall, and diversity done well tends to improve performance, so it might have nothing to do with the women themselves at all--they may simply be a reflection of a thoroughly well-run company.

So while it's possible that there's the disparity you talk about for the reason you talk about, we should hold that view very tentatively indeed.

And anyway, the women who are answering those surveys aren't CEOs.

Doesn't it make sense instead to look for what things are generally correlated with happiness, see which of those have declined, and tentatively blame those factors as the most likely causes?

For instance, happiness increases with strong community bonds; but most economically advanced communities are more fragmented. Happiness increases with more leisure time and with more respect for leisure time; but the U.S. especially has a population that is both busier and in a more always-on culture.

The Cassandra effect is one specific way in which one could have expectations that exceed what reality can deliver (and that matters: https://greatergood.berkeley.edu/article/item/how_to_manage_expectations_to_maximize_happiness). But there are a lot of ways that expectations could exceed reality (indeed, advertising is largely about trying to convince you that your own reality isn't as good as you need; Instagram is largely about trying to convince everyone else that your reality is awesome which inadvertently makes theirs feel bad, and yours too when you look at what they're posting), and men's happiness has been going down for years too (just a bit less), so singling this out seems a little odd.

I also wonder what the changes have been in the messages that the culture has been sending. "You have an absolute right to blissful euphoria!!" is a pretty good way to make anyone who believes it rather miserable, even if things are pretty darn good and getting better. With all the positive pep-talk and anti-negativity, we could well be actually talking ourselves out of happiness when we notice that, huh, how things actually are don't match all those honeyed words.