keys1: "The survival of Qwerty is surprising to economists only in the presence of a demonstrably superior rival. David uses Qwerty's survival to demonstrate the nature of path dependency, the importance of history for economists. and the inevitable oversimplification of reality imposed by theory. Several theorists use his historical evidence to claim empirical relevance for their versions of market failure. But on what foundation does all this depend? All we get from David is an undocumented assertion and some advertising copy."