Tuesday is the deadline for Americans to file their tax returns, but according to one think-tank, they may as well not bother.
Investigation of US tax dodgers is "in a shambles", says the Transactional Records Access Clearinghouse (Trac) at the University of Syracuse, which monitors the performance of federal agencies.
Trac found that prosecutions for tax offences had halved in the past 10 years, and investigations had fallen by one-third.
At the same time, Trac alleged that the Internal Revenue Service (IRS) - the US's tax authority - had started deliberately to focus on small offenders, while turning a blind eye to malpractice by corporations.
Don't blame us
The IRS was quick to deny Trac's allegations.
It quibbled with Trac's use of Department of Justice data, which it said underestimated the extent of IRS investigations.
The volume of tax investigations has fallen slightly over the past decade, the IRS admitted, but it insisted that a significant number of long-term cases were in the pipeline, which would push up future figures.
The increasing complexity of corporate and individual tax arrangements has meant that investigations take much longer to bear fruit, the IRS argued.
It also protested that its agents were becoming increasingly overstretched: the number of tax returns filed has grown 12% in the past 10 years, while there are one-quarter fewer agents capable of auditing them.
Big and little
Whatever the rights and wrongs of the argument, the IRS is certainly focusing far more on individual than on corporate taxpayers.
Last year, US corporations accounted for just over 10% of the country's tax revenue, down from 16% in the 1970s.
The IRS now takes almost 28 cents of every individual's dollar, compared with 26 cents of every corporate dollar.
According to critics such as Trac, this is culpable negligence at a time when the fiscal behaviour of many large US companies leaves much to be desired.
But conversely, the US has comparatively high corporate tax rates, and could be seen as moving more into line with other developed economies.