The main reason I am unable to come up with complete definitions is that I am not an economist. But my personal ignorance is hardly an argument against government regulation of economy.
The system does cock up now and then, yes. But when you sum it all up, it does more good than harm. The problem is that you won't settle for anything less that perfection, which doesn't exist in real world.
Anyway, I find it odd that you disagree on having health and safety standards. I don't know about you, but I prefer living in a world where I don't have to fear getting trichinosis from eating pork or having a bridge collapse under me as I drive across.
As for pollution, what if there is no immediate victim other than nature itself?
Oh, and there is punishment/reward for bad/good governing. It's called elections.