The tax gap – the difference between taxes owed and taxes paid – is the holy grail for experts in the field because finding a way to close it by increasing compliance would result in significantly more revenue for the U.S. government. The latest figure, for 2006, is just a littles less than the current size of the U.S. budget deficit. The chart shows estimates of the gross tax gap, which doesn't include taxes eventually paid through enforcement and other means.
