Answer:

Widening income inequality is the defining challenge of our time. In advanced economies, the gap between the rich and poor is at its highest level in decades. Inequality trends have been more mixed in emerging markets and developing countries (EMDCs), with some countries experiencing declining inequality, but pervasive inequities in access to education, health care and finance remain.

Wealth is now even more concentrated at the top level, exacerbating the overall disadvantage of low-income households. In 2012, the bottom 40% owned only 3% of total household wealth. In contrast, the top 10% controlled half of all total household wealth and the wealthiest 1% owned 18%. The top 1% share almost 10% of total income worldwide.