Michael Wolraich: I have tools in my house that I'm pretty sure came from handy, handymen and contractors who just left them here. And so now to me that's just a, I love that gift aspect of book lending. But with a power tool, it's not such an easy. Right? So of course, you asked about anticipating questions. My question about the drill is, why don't we have that already? He says he wants to talk about the different kinds of transaction costs - how that creates a set of limits on potentially on what can be shared and what can't be,. or what is unlikely to be shared because it doesn't work economically.