The most obvious way to do it would be:

* Get a sample of 100 random people or so

* For each person, have them track their time

* For each thing you have them tracked doing, estimate how much it would cost to get someone else to do it

But it pretty quickly gets difficult around questions of entertainment. If I go dancing for fun, should you count how expensive it would be to hire a professional to dance in my place? If I woodworking or knit for fun but then I also give away the things I make to my friends as presents should we count that at market value?

> But it pretty quickly gets difficult around questions of entertainment.

Not just question of entertainment, but also personal hygiene.