Institute for Taxation and Economic Policy, July 2013. The potential fiscal costs of legalizing undocumented immigrants have been central to the immigration reform debate. This report contributes the most reliable figures available about the potential benefits to state governments, showing that the 11.2 million undocumented immigrants living in the United States are already paying a significant share of their income in state and local taxes, and that figure would rise under immigration reform.

http://www.itep.org/pdf/undocumentedtaxes.pdf