How much value do public markets add?
It wasn’t much of a debate, sadly, when I talked the decline of the public markets with Andrew Ross Sorkin: he told me that he pretty much agrees with me. He did manage to drag an actual policy prescription out of me, though — the idea that some kind of Tobin tax might alleviate the problem a little. But truth be told, I’m still not sure just how big the problem is. Has anybody ever tried to quantify the societal benefit of public stock markets, or the social harm that might be done if Facebook just stays private? Where would you even begin?