A Quick Comment on "Unknown Unknowns"
Mainstream economics has a lot of answers for how we attack the first - namely, the idea of "search." But it has fewer answers for the second: how do we "discover" that which we don't know we don't know. The Austrian argument is precisely that markets are better at the second than the various alternatives.
Distinguishing between the known unknowns and the unknown unknowns is a very important step in any decision making process, as is thinking about the best methods for making either type of unknown into a known. I have no love for Rumsfeld, but making fun of him for that comment isn't fair. He is making perfect sense.