"protecting American jobs"

Taking externalities into account isn't hindering others, since the externality is by definition an unwanted imposition pf costs on a third party that didn't exist prior to the economic activity that generated it. I fail to see how this is different from an unpaid bill, and Nobel laureate Ronald Coase has rather convincingly argued* that the costs of mitigation in advance or in arrears ends up being the same, but that the transaction costs of enforcing property rights against externalities are a sufficient barrier to many pollutees that polluters are often willing to gamble on others' inability to adequately enforce their rights and pocket the resulting savings.

* in The Problem of Social Cost, an unusually readable essay for the field of economics.

Yeah, I knew you were being a bit hyperbolic but this is a bit of a touchy issue for me (see other comments on this thread) so I apologize for my sharp tone.

Obvious examples would be people like aid workers, religious clergy and others who ostensibly hew to some unselfish non-discriminatory ethical code, but as well know such activities often sacrifice material wealth in exchange for significant social currency, plus there's a disappointingly high proportion of predatory types to be found among those ostensibly caring for the most vulnerable. I don't have the paper to hand now and can't remember enough to look it up but I was surprised last year to discover that people with sadistic tendencies (as measured by clinical instruments) are over-represented in the paramedic profession, for example.

One group that I am inclined to think is extraordinarily concerned with maintaining a level playing field even at their own personal expense is the community of economic theorists, although this claim might seem pretty counter-intuitive at first glance. It also gives rise to a weakness at the heart of the profession; economists are so concerned with discovering objective criteria for efficient outcomes that they don't have a don't have a good model for greedy or altruistic behavior, and until fairly recently have relied instead on the conceit of everyone being rational utility maximizers, much as you did in your grandparent comment. This implicit assumption has led to the discipline being long labeled as 'the dismal science,' notwithstanding the majority of its practitioners' positive rather than normative aims.