If people had to pay the true cost of their decisions up-front, we'd make a lot of different decisions. That said, I got quite into this stuff a few years back

If people had to pay the true cost of their decisions up-front, we'd make a lot of different decisions. That said, I got quite into this stuff a few years back, and determining "true" cost can be harder than it sounds. Externalities, positive or negative, have to be measured against a baseline, and deciding on where that sits is subject to opinion and bias.