5Bernstein, David P. , A Revised Note: What is the Appropriate Tax--Base/or President--Elect Obama's High--Income House- hold Tax? ER3. (November 12, 2008), Working paper series.
6see "obama to push for higher social security tax"[OL], http:// www. msnbc, msn. com/id/Z1739271/.
7Hausman. J, " Taxes and labor supply " in Auerbach, Alan and Martin Feldstein,Eds. Handbook of public economics [M]. Volume 1, Amsterdam, 1985.
8Nada Eissa: Taxation and Labor Supply of Married Women: The Tax Reform Act of 1986 as a Natural Experiment[R]. Georgetown University; National Bureau of Economic Research (NBER) ,this article is for the working paper , No. W5023, February, 1995.