the allocation of income and assets across the population, and thereby affects levels of inequality and human rights enjoyment".15 It is time that these calls be heeded. a) Progressivity of taxation as a human rights requirement Redistributive fiscal policies and social spending, particularly on social security, have had a major role to play to reduce the levels of inequality that would result from market incomes for different groups of the population. In OECD countries, public cash transfers, together with income taxes and social security contributions, were estimated to reduce inequality among the working-age population (measured by the Gini coefficient) by an average of about one-quarter across OECD countries during the period from the mid-1980s to the late 2000s.16 Few graphs illustrate this contribution of redistributive public policies better than a graph presented by the OECD in 2011, which contrasts the levels of inequality resulting from market incomes alone with the levels of inequality resulting from net incomes, i.e., after taxation and redistribution are taken into account. Combining progressive taxation schemes with subsidies to various forms of social protection, it appears, reduced inequality within the working-age population by about one quarter, on average, in OECD countries, and the impacts are even larger in Nordic countries, in Belgium or in Germany. The following figure illustrates this impact: Fig. 1. Impacts on inequality (measured as Gini-coefficient) of the difference between market incomes and net (disposable) incomes following taxation and social security transfers, OECD countries, late 2000s (data from 2006 to 2009, depending on the data available for each country). Source: OECD, Divided we Stand. Why Inequalities Keep Rising (2011), chap. 6, fig. 6.1. Both by reducing the weight of pre-tax income inequalities and by increasing the fiscal capacity of the State, a progressive tax system has an important role to play in the fulfilment of social rights. The Committee on Economic, Social and Cultural Rights has therefore regularly expressed its concern at reforms of the taxation system that would make it less progressive (for instance, by shifting the burden from corporations to the families, or by increasing VAT rates on essentiel items): in Concluding Observations addressed to the United Kingdom, it deplored "the adverse impact that recent changes to 15 Report of the Special Rapporteur on extreme poverty and human rights, Philip Alston, to the 29th session of the Human Rights Council (A/HRC/29/31) (26 May 2015), para. 53. 16 Organisation for Economic Co-operation and Development, Divided we Stand: Why Inequality Keeps Rising (OECD, Paris, 2011). 8 CRIDHO Working Paper 2017/1