"The effects of low literacy cost the U.S. more than $225 Billion each year in non-productivity in the workforce and loss of tax revenue due to unemployment.  Individuals at the lowest level of literacy have a higher rate of unemployment than the national average-- 14.5 percent in 2011."

Source: "The Numbers Don't Lie." ProLiteracy. ProLiteracy Worldwide, 2013. Web. 27 May 2014.
Link: http://www.proliteracy.org/the-crisis/adult-literacy-facts