Social justice is based on the concepts of human rights and equality and involves a greater degree of economic egalitarianism through progressive taxation, income redistribution, or even property redistribution. These policies aim to achieve what developmental economists refer to as more equality of opportunity than may currently exist in some societies, and to manufacture equality of outcome in cases where incidental inequalities appear in a procedurally just system. The Constitution of the international labor organization affirms that "universal and lasting peace can be established only if it is based upon social justice.