Het nog onbekende niemandsland van belastinguitgaven. Een analyse van de omvang en sociale verdeling van de overheidsuitgaven voor tweedepijlerpensioenen van werknemers in België.

Second pillar pension accumulation for employees in Belgium is promoted by granting different types of tax reliefs (including preferential social security contributions). Contributions to the second pillar are subject to lower taxation compared to the same amount paid out as professional income. Also, the interests generated in a second pillar pension product are generally tax-exempt, whereas interests generated in a standard savings product are taxed. Upon withdrawal, second pillar pension payments are taxed, while funds withdrawn from a standard savings product are generally tax-exempt. This taxation at the point of withdrawal only partially offsets the preferential tax treatment of second pillar pensions during the contribution and interest phases. Granting tax reliefs for second pillar pension thus leads to government revenues foregone. Because these revenues foregone are comparable to government expenditures, they are often referred to in the literature as social tax expenditures. The Belgian government has long been aware that tax reliefs for second pillar employee pensions place a burden on the public budget. Yet, the available information faces significant limitations. Since the late 1980s, social tax expenditures have been annually recorded in the so-called 'Inventory of Federal Fiscal Expenditures', which is added as an annex to the State Budget. However, the figures in this inventory do not account for the reliefs in social security contributions, the reliefs linked to employer contributions, the tax reliefs on generated interests, nor do they include the tax income collected from taxing pension payments. Moreover, these figures lack sufficient detail to examine the social distribution of the tax reliefs granted. As a result, there is still insufficient knowledge about both the size and the social distribution of social tax expenditures for second pillar employee pensions. Using administrative data on second pillar pension accumulation from the Belgian db2p-database, this PhD research provides the first comprehensive overview of the budgetary and distributional impact of social tax expenditures for Belgian second pillar employee pensions. The budgetary impact of tax reliefs for second pillar employee pensions varies between 1.6 to 2.1 billion euro in 2019, depending on the method and approach used to calculate social tax expenditures. This means that, depending on the approach and method chosen, tax reliefs for second pillar employee pensions cost the government between 1.6 and 2.1 billion euro in 2019. According to the Belgian inventory data, social tax expenditures for second pillar employee pensions amounted to only 121.4 million euro in 2019. Social tax expenditures calculated in this dissertation are thus significantly higher than those reported by the Belgian government. Furthermore, social tax expenditures for second pillar employee pensions are unequally distributed. This is because men, older employees, highly educated workers, white-collar workers, private sector workers, workers enrolled in a company pension, and high-income earners benefit most from this type of government support. The unequal distribution of social tax expenditures across income groups is particularly striking. This PhD research uncovers a pronounced Matthew effect, as nearly 60% of tax subsidies flow to the 10% of employees with the highest incomes. The findings of this PhD research emphasise the need for Belgian policymakers to account for social tax expenditures linked to second pillar employee pensions when designing pension policy. After all, the tax reliefs granted by the government turn out to be more costly than previously thought on the basis of the inventory, and they primarily benefit employees with very high incomes.