Yes, it should be common sense that people think that way, but there's an expectation that this not apply to marriage.
And I think this is what is causing marriage rates to plummet. People are responding to incentives and the incentives are increasingly stacked against marriage.
Agree completely - with the caveat that the perceived incentives (and costs) are dependent upon each individual.
In the crime example, some will not become criminals no matter the perceived benefits...one would say the personal emotional cost to their psyche by stealing (for example) would not outweigh the benefits.
Same with any decision...each individual remains the arbiter of their own cost-benefit analysis.
