Last week, the Social Security Trust Fund report was released. One of its more telling charts was of the trend in Social Security revenue. Social Security revenue comes from a tax on the wages of earners, paid by both employees and employers. So, essentially it tracks the level of employment. Based on the simple trend of revenues from 1990 to 2007, just before the Great Recession started, 2012 revenue would have been $899.4 billion; instead, it was $840 billion.  That gap means less money to build up the Social Security Trust Fund than expected. The trustees do not break down the revenue by the age of workers, but based on the dramatically lower employment experience of young workers, the bulk of that gap reflects the lost wages of young people.