How much money does the U.S. lose due to corporations moving to avoid taxes

How much money has the United States lost due to tax inversion?  Well it's difficult to get an exact number, but it is estimated to be in the billions.  "Congress’s Joint Committee on Taxation projects that failing to limit inversions will cost the Treasury an additional $19.5 billion over 10 years — a number that seems way low, given the looming stampede. But even $19.5 billion — $2 billion a year — is a lot, if you look at it the right way. It’s enough to cover what Uncle Sam spends on programs to help homeless veterans and to conduct research to create better prosthetic arms and legs for our wounded warriors." (Washington Post)  Other analysts think the number is much higher.  We have to close the loopholes in the tax laws to prevent inversion and hold these companies accountable.