Tax evasion is an illegal attempt to defeat the imposition of taxes by individuals, corporations, trusts, and others. Tax evasion often entails the deliberate misrepresentation of the taxpayer's affairs to the tax authorities to reduce the taxpayer's tax liability, and it includes dishonest tax reporting, declaring less income, profits or gains than the amounts actually earned, overstating deductions, using bribes against authorities in countries with high corruption rates and hiding money in secret locations.
Tax evasion is an activity commonly associated with the informal economy. One measure of the extent of tax evasion (the "tax gap") is the amount of unreported income, which is the difference between the amount of income that should be reported to the tax authorities and the actual amount reported.
In contrast, tax avoidance is the legal use of tax laws to reduce one's tax burden. Both tax evasion and tax avoidance can be viewed as forms of tax noncompliance, as they describe a range of activities that intend to subvert a state's tax system, but such classification of tax avoidance is disputable since avoidance is lawful in self-creating systems. Both tax evasion and tax avoidance can be practiced by corporations, trusts, or individuals.
In 1968, Nobel laureate economist Gary Becker first theorized the economics of crime, on the basis of which authors M.G. Allingham and A. Sandmo produced, in 1972, an economic model of tax evasion. This model deals with the evasion of income tax, the main source of tax revenue in developed countries. According to the authors, the level of evasion of income tax depends on the detection probability and the level of punishment provided by law. Later studies, however, pointed limitations of the model, highlighting that individuals are also more likely to comply with taxes when they believe that tax money is appropriately used and when they can take part on public decisions.
The literature's theoretical models are elegant in their effort to identify the variables likely to affect non-compliance.