Watching how my kids spend money, I'm constantly reminded of something rather obvious, but still instructive: They are far less profligate with their own cash than they are with mine. What's 40 bucks for a concert if it comes right out of Dad's wallet? But that same concert is far less of a must-see event if they've got to spring for it out of their own piggy banks. My kids would explain this economic principle with one word: "Duh." People are much more careful with their own resources than with others' resources or with those resources that are publicly owned....