qualification whatsoever we have results for profit when the system is supplied limited in a sense I'll make precise and then there's similar numerical results for welfare but the theory there is actually a bit more challenging and so I'm not going to claim anything for that in the talk okay so let me start by modeling sort of the strategic side of the problem and this is another point which we'd say you know very little about we don't say anything in our paper on and I think it's an interesting issue is that we're going to just assert that