INTRODUCTION Inequality impairs human dignity, causes and perpetuates poverty and limits the enjoyment of human rights. Inequality is a barrier to participation in economic, social and political life. It restricts the life chances of people and serves to oppress and marginalize entire communities. Beyond the experience of those directly affected, unequal societies are more likely to be beset by health and social problems ranging from higher levels of incarceration, violence and other social problems, to lower levels of social mobility.1 Inequality undermines social cohesion and fosters conflict. It exacerbates the exclusion of minorities and other marginalized groups. Above all, it embeds unfairness, with powerful negative consequences for people and communities. In 2015, 193 States came together to affirm the 2030 Agenda for Sustainable Development. In so doing, they pledged that “no one will be left behind” in this new global effort to eradicate poverty, secure human rights and protect the planet.2 This statement reflected the recognition that sustainable development can only be achieved by addressing inequality, a fact reinforced by Goal 10 of the Sustainable Development Goals on reducing inequality within and between States, Goal 5 on gender equality and the large number of other goals and targets focused on equality of access, participation and outcome. This central status of equality in the 2030 Agenda echoes its primary position within the Universal Declaration of Human Rights, adopted in 1948. Born out of the horrors of the Holocaust and the atrocities of the Second World War, which witnessed the extermination of “millions of Jews, hundreds of thousands of Roma and Sinti people, people with disabilities, homosexuals, prisoners of war, political dissidents and members of Resistance networks”,3 the Universal Declaration of Human Rights places the rights to equality and nondiscrimination at the heart of the human rights system. Article 1 affirms that “all human beings are born free and equal in dignity and rights”. Article 2 makes clear that human rights should be afforded to everyone “without distinction of any kind”. These two global declarations, proclaimed more than 65 years apart, demonstrate States’ recognition that efforts to create just, inclusive and peaceful societies, to eliminate poverty and to ensure enjoyment of human rights all require a focus addressing inequality. Inequality and the right to non-discrimination Inequality takes many forms and has myriad causes – economic, social, political and cultural. As such, creating a world in which all can and do participate equally requires a coordinated, collaborative and comprehensive approach. The elimination of discrimination is a key part of this puzzle: there can be no equality in situations in which persons and groups are treated unfavourably or subjected to disadvantages on the basis of their status, beliefs or identity. Indeed, this has been widely and consistently recognized by States, through their adoption of international human rights instruments that place the right to non-discrimination at their heart. The adoption of comprehensive anti-discrimination laws – laws that have the purpose and effect of prohibiting all forms of discrimination – is an essential step in the effort to realize the right to non-discrimination. Without the enactment of laws that prohibit all forms of discrimination on the basis of all grounds recognized in international law and in all areas of life regulated by law, provide for the effective enforcement of the right and mandate positive action measures to address historic or structural discrimination, States will be unable to give effect to the right to non-discrimination. It is only by ensuring the effectiveness and enjoyment of the right to non-discrimination that States will realize their ambitions to combat inequality. xx 1 See, for example, Richard Wilkinson and Kate Pickett, The Spirit Level: Why More Equal Societies Almost Always Do Better (London, Allen Lane, 2009). 2 General Assembly resolution 70/1. 3 Office of the United Nations High Commissioner for Human Rights, “75 years after Auschwitz – Holocaust education and remembrance for global justice”, statement by Michelle Bachelet, United Nations High Commissioner for Human Rights, 27 January 2020.