Economics is complicated because at a fundamental level you're trying to understand people and their decisions. Sorry but you're really never going to "solve" that problem. Stuff will forever be a theory.
You are also assuming that the economist is teaching this and saying "this is how it works, it's 100% accurate" and not starting off with "this is a theory, and we work towards making it better over time with new data and new ideas." Just because something may not be 100% perfect does not mean you don't strive to improve what you have and you won't improve what you have if you just let it rot on the vine and not teach the next generation.
The biology one is even more convoluted. Having an _interest_ in something does not mean you have to "be" the interest. A simple example, I work to live, not live to work. I am not my work. My work is only here to support me living my life. You are claiming that the biologist is a failure because they didn't want, or couldn't, create offspring despite their interest being in evolutionary biology. That's some kind of weird argument to make there man...
Would you expect experts in criminal psychology to be serial killers?
But I see no relation whatsoever between expertise in evolutionary biology and the decision to have children.
> I don't believe 100% that this is how the world works enough to bet my own money, but I am going to tell hundreds of students every year this is how the world works
This is a fundamental misunderstanding of what a good professor does. If the economist acts in this way, they have failed as a teacher, not as an expert in economics. Likewise I think you have a fundamental misunderstanding of economics as a science - it's not one, and it sounds like the economist was making a quip at the predictive weakness of the field overall.
> The biologist story is subtler.
No, it's not. You're just having to push harder to keep it afloat.
> One could argue that failure to become a parent signals that you deeply, fundamentally, don't get biology
One would be wildly wrong to make that argument. Once again, I think this shows a deep lack of understanding on your part of the field itself and what it means to study a field. And also what it means to have a child as a human, honestly.
> economists and biologists vs financial advisors and engineers is that we expect the later to have skin in the game but for some reason allow the former to not have to
Is this not obvious? You're reaching very hard to dig at researchers in a way that indicates you don't know what research actually is. Or maybe you're defensive of the work you do? I shouldn't speculate too hard here or I risk also being this wrong.
This is complete and utter nonsense.
So farm animals understand biology better than the biologist does?
If the economist weighs the risk to not put too much stock in these theories (no pun intended actually), why does he not likewise hesitate to teach these theories to his students? Like "I don't believe 100% that this is how the world works enough to bet my own money, but I am going to tell hundreds of students every year this is how the world works."
The biologist story is subtler. One could argue that failure to become a parent signals that you deeply, fundamentally, don't get biology - despite your superficial interest and theoretical knowledge? Like, you may talk about zygotes all day but you failed to make one...
Maybe the difference between economists and biologists vs financial advisors and engineers is that we expect the later to have skin in the game but for some reason allow the former to not have to.