and henry aaron is with the brookings institution.ntlemen, if we begin from the agreement that there is a problem, given the number of future retirees and the future revenue stream that's projected for them to collect from, how would you describe its size and extent? david john? >> i'd say that it's serious but not critical. we have a number of... well, the baby boomers are going to be retiring fairly soon, and more baby boomers that retire, the worse the program is going to be. it's already running cash flow deficits at the moment. it will continue to run cash flow deficits according to the social security administration for the next 75 years at least. >> reporter: henry aaron? >> i would describe the situation as one where the system is fundamentally sound but has modest long-term problems that should be addressed as soon as a politic agreement can be reached between the two parties to address both an increase in revenues and if necessary a modification in the benefits, as well. but it's not a crisis. there's in great urgency to do