come up with a worse idea but no one picks it up, no one takes it off. if you come up with a better idea it spreads at the expense of the baddie and the recombining and what we do. the more we trade, the more we exchange, the more it happens. >> and the better life gets in general. >>guest: absolutely. our living standards have shot up in my lifetime. the average income of the average person is throw times what it was when i was born and life span is 30 percent longer and child mortality is two-thirds lower that is because we keep improving each other's living standards. >> so, you like to show people this picture. >>guest: the object on the left is a hand a and from half a million years ago and sits on my desk at home, the hand ax and next to it is the computer mouse, and they are the same size and shape and the ax was