INTRODUCTION
Surveys usually draw a line between legal under-reporting of tax obligations, known as tax avoidance, and illegal undervaluation, or tax evasion. In the field of economics, however, it is impossible to distinguish between the two (Lipatov, 2005). In this situation, it makes sense to split these understatements into simple and sophisticated, rather than into evasion and avoidance. Simple tax evasion means not using either specialized accounting or financial specialists. Fiscal responsibility of substatements that require special knowledge will be called sophisticated tax evasion [sophisticated tax evasion: Lipatov (2005)]. It is noteworthy that there is no measurement of any type of tax evasion available. Schneider (2006), for example, used informal sector as a proxy to tax evasion. Sophisticated evasion prevents such attempts, because arrangements that are more complex are being considered. Therefore, we observed large cases of inspection and audit in proportion of tax revenue from taxpayers in total tax revenue. In the US, as noted by Slemrod (2004), the latter US fell from 6.4 percent of GDP in 1951 to less than 1.5 percent of GDP in recent years. Indirect evidence for the maintenance of sophisticated evasion is provided by the fact that the largest taxpayers in the US have paid less tax in the last three years, even when they increased yields, as shown by Browning (2004). To solve this problem, many countries have made tax reforms and introduced revenue mobilization (Bekoe et al., 2015). However, academic papers in this area are scarce. Tax evasion with specialists has increased in all sectors, because they need to submit their reports to audits by tax authorities regularly (every three years in most countries).
