Sure, it may be an educated guess, but we have to try. It's better than the alternative, which is to assume that any job that pays (and thus is from a company

Sure, it may be an educated guess, but we have to try. It's better than the alternative, which is to assume that any job that pays (and thus is from a company that earns profit) has equal impact or externalities with all other companies. A lack of clarity shouldn't be an excuse for not trying.