(Leave political philosophy debates out of this, ie. "It doesn't matter, social security shouldn't never have been enacted")



I'm looking at the 2011 federal government budget charts on Wikipedia.


Expense:



Income:




That means there was a difference of approximately $100 billion between SS expense and income last year, which one would think is a good thing! However, everyone's worried about social security wrecking the economy and federal debt in the future. I read this, also from Wikipedia:

Because of the mandatory nature of the program and large accumulated surplus in the Social Security Trust Fund, the Social Security system has the legal authority to compel the government to borrow to pay all promised benefits through 2036, when the Trust Fund is expected to be exhausted. Thereafter, the program under current law will pay approximately 75%-78% of promised benefits for the remainder of the century.



So can anyone explain to me the economics behind how the social security system will go from being ahead in 2011 to far behind in 2036? I don't understand what factors are involved in this.



http://en.wikipedia.org/wiki/United_...federal_budget