So how about that bit about the happiness of your neighbor having to come at the expense of someone's unhappiness? Not so. There is plenty of happiness to go around, if one but works at it hard enough, finds worthwhile things to do, which is open to everyone, especially in a free enough society. And what about America's riches causing the poverty of Third World countries? Completely off the wall - just as when one goes shopping, both the seller and buyer can make gains with no harm to either, the richness of one country can happily coexist with that of another. There are enough differences among human beings that the process of open exchange will most likely secure for them all a measure of enrichment without incurring the loss of another. No one in the world must be poor in return for some people being rich.
Well, duh! :-)