Reading this I tought "Huh, simplified economic concepts, ending on overpushing the idea of voluntary transactions a bit...smells a bit american-libertarian".
None of the concepts are wrong, but things are more complicated. For a short summary on the idea of Inequality of Bargaining and consequential hollowing of the "voluntary" transaction you can check out https://en.wikipedia.org/wiki/Inequality_of_bargaining_power
Interestingly, one area where this is taken into account, is study design (i.e. thinking about when a reward will skew the results/be unethical towards participants)
I think you're right, things aren't that simple, but I have the feeling when I used these 3 points in the past, things went better.
But on the other hand, I always have the feeling, relationships go better if they aren't emotionally evaluated too much.
Sunk Costs
I've seen relationships go to shit but people are like "we are together for 10 years now, I can't leave them!" even in face of domestic violence or general abuse.
Yes the 10 years were nice and you paid them with your lifetime, but do you want to pay the shitty part too or just leave it by the 10 nice years?
Nothing is Free
I've seen relationships between people who simply don't fit together, but one part wanted to keep the other around, because of ... reasons? The other was way out of their league, attractive wise, and knew it. The other part was rich, and knew it.
Sometimes the other part was even the almost perfect fit, but didn't get their life in order.
Revealed Preferences
I've seen so many people who say A and do B. Especially in relationships. Talk is cheap and I did it too, in the past, but if you always say you want kids and never have them, time is over someday.
Click around...project of IHS...
https://en.wikipedia.org/wiki/Institute_for_Humane_Studies#O...
None of the concepts are wrong, but things are more complicated. For a short summary on the idea of Inequality of Bargaining and consequential hollowing of the "voluntary" transaction you can check out https://en.wikipedia.org/wiki/Inequality_of_bargaining_power
Interestingly, one area where this is taken into account, is study design (i.e. thinking about when a reward will skew the results/be unethical towards participants)
For some discussion see: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3646546/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2600442/ https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2600442/#S2titl...