but, first, let me say thanks to c. a.p. and to you for inviting me.the one hand, it's very gratifying to hear stuff that i've been saying for 25 years now coming out as conventional wisdom from people as sharp as lily and john. on the other hand, i have to go third, and they've taken most of the sensible, thoughtful points. [laughter] so i'll try to, i'll try to weigh in on different aspects of this. the way i think about it is that, broadly speaking, there's four ways that government can influence retirement accumulation. the first one is mandates. and it goes without saying, but i'm going to say it anyway, that social security is at core of the retirement system. it should be there, it should be a mandate for the reasons john mentioned, and that's sort of the building point from any additional discussion of retirement policy. the second way in addition to mandates is incentives, of course, tax incentives. tax expenditures, whatever you want to call them. and there's a wide variety of them with a somewhat checkered history as lily and john have descr