We analyze both the theoretical framework of labor taxation in the open economy and important current reforms of labor taxation in countries worldwide including the introduction of "social VAT". The current tax theory considers the reforms of labor income taxation related to the shifting of taxation from more mobile tax bases to the less mobile ones, taking into consideration the reduction of tax rates with simultaneous broadening of the tax base. Such a reform is intended to reduce the distortion effects of taxation, and, as a consequence, to reduce the tax burden on labor. The empirical section includes analysis of indicators of labor income taxation in OECD countries. We calculated the progressivity index of overall tax wedge and its components - personal income tax, employer's and employee's social security contributions. The results enabled cross-country comparisons: we found that in a most OECD members both employees' and employers' social security contributions systems are regressive or flat, while personal income tax systems are progressive in all countries except Hungary with flat tax schedule. Moreover, in OECD countries with highest GDP per capita the employees bear average labor tax burden with simultaneously low employers' social security contributions rates.