Solvency of a PAYGO Program

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Here is a different way to look at Social Security solvency. When the solid line drops through the dotted line, the contributions are not enough to cover the costs. This correspondes to the date when we will need to start using the interest from the trust fund. The chart helps make it clear that a pay as you go (PAYGO) program [which would not have any interest to draw on] that works for one demographic is not balanced when the demographic is changed.