> What number of QALYs can be calculated for an average worker of other professions, especially those recommended by the 80000 hours site (e.g. QALYs saved by an average "Think tank researcher")?

When you say "average", do you mean a marginal worker of average quality, or the literally the total impact of the profession divided over its total practitioners? The definition really isn't relevant for s careers because we expect diminishing returns, and individuals can only act on the margins. (On the other hand, the government might be interested in it if they had the ability to expand the size of the entire industry.)

I don't know what the estimates are, but I would wager heavily that there are identifiable think-tank research positions with much higher leverage, even on the margins, than the highest-impact medical professions. It's just a matter of multipliers: think tanks influenc large amounts of money while doctors generally can't help beyond their own patients.

> - Is it even possible to calculate average QALYs in a way to really compare anything meaningful, across the different occupations? If not, why are they here calculated for doctors?

Yes, I think an estimate is possible, although there may be large uncertainties. 80k Hours has previously estimated the value (and chance) of things like becoming a member of parliament, or working in finance and donating most of one's salary to health charities in the developing world. Even when these are off by an order of magnitude, they often are sufficiently informative to usefully change people's plans.

80k Hours claims that over 180 people have made serious career changes that those people explicitly attribute to the organization's research.