The First Economic Deadly Sin

David Frum: Is there some evolutionary reason why humans might tend to make certain predictable mistakes? He says the first economic deadly sin is seeing the world in zero-sum terms. In a free society or an open society, if you and I mutually engage in mutually voluntary transaction, then we're both gaining, he says. Those kinds of mutually voluntary, mutually beneficial transactions are much more characteristic in a commercial society than positive sum ones that lead to net gains.