Résumé
If we measure wealth on the yardstick of goods and services consumed and produced, the world has never been as rich as in 2015. And never has this wealth been so unequally distributed. The share of wealth owned by the wealthiest 1% or 10% is once again, in countries were tax data is available, at the record levels of the beginning of the previous century. Seven people out of ten live in a country in which the gap between the rich and poor is wider than 30 years ago (Oxfam, 2014 according to Milanovic, 2013). In OECD countries, the gap between rich and poor has never been wider: the income of the wealthiest 10% is 9.5 times that of the poorest10% (OECD 2015); in the 1980s, the ratio was 7 to 1. In the rare countries of Latin America where inequalities have decreased, the Gini coefficients, which measure income inequalities, are still high. In South Africa, the Gini coefficient was lower in 1995 (0.56) at the end of apartheid than in 2009 (0.63) (Oxfam, 2014). These income inequalities nourish and reinforce inequality where health, education and gender (70% of the poor are women - Cortinovis and Rivière, 2015), territory (between urban and rural populations) and, in some cases, ethnic inequality are concerned (in New Caledonia, a Kanak has 7 times less chance of graduating from higher education as a non-Kanak, Ris, 2013). The increase in inequality we can observe in countries can also be seen on a global scale. In 2016, half the world's wealth will be owned by 1% of the population of our planet (Global Wealth Report 2015). However, for the first time, the reduction of domestic income inequality is on the menu of the international agenda. It figures explicitly among the Sustainable Development Goals (SDGs) adopted in September 2015 by the United Nations. Let us remember that the Millennium Development Goals, which had been oriented towards international cooperation since 2001, did not deal with income inequalities and focused on extreme poverty and access to basic services. In addition to this, they only concerned developing countries, as opposed to the SDGs which apply to all countries. How have economic inequalities become a universal problem which clearly calls for a coordinated political answer? Why is the increase in inequalities not sustainable? Why have inequalities widened and how can they be reduced from a practical point of view? What role in particular is international cooperation for development likely to play?