The National Center for Policy Analysis yesterday released Tax and Social Security Reform: Thinking Outside the Box, by Hans Fehr (University of Wuerzburg), John C. Goodman (National Center for Policy Analysis), Sabine Jokisch (University of Wuerzburg) & Laurence J. Kotlikoff (Boston University, National Center for Policy Analysis & National Bureau of Economic Research).  Here is the Conclusion:

To remain competitive in the modern international economy and to avert the crushing burden of unfunded elderly entitlements, we need both tax reform and Social Security reform. Some have supposed that these are two completely separate endeavors. In fact, the two reforms may be easier to adopt and implement if they are combined.