Unsurprisingly given the two- way connections between them, the rising concentration of contemporary power has coincided with the rising concentration of income and wealth. A widening of economic inequality, characterized by especially fast- rising prosperity at the top of the distribute since the 1970s, has been demonstrated across Europe, North America and larger newly industrializing countries, and given a range of mainly economic explanations (e.g. Piketty 2014, Atkinson 2015, Stiglitz 2012). Rising inequality challenges the long- held assurance of the Kuznets curve, that economic inequalities would initially rise with per- capita national income, but subsequently fall. It suggests that factors causing societies’ income and wealth distributions to become more even as they get richer (including the spread of education, redistributive taxation, welfare states and democratization which enforces these) may not be as strong as previously expected, or may be outweighed by forces that worsen the inequality. Intra- country inequality appears to have widened even as inter- country differences (in per- capita national income) diminish, through lower- income countries outgrowing and ‘catching up’ those that industrialized earlier.

Disproportionate income and wealth gains at the top end of the distribution, alongside stagnant or falling economic fortunes further down, have important political effects. They can undermine an existing pact between elites and the social classes immediately below them, while creating unity between previously disparate social groups which now share a common sense of relative deprivation. In many countries, systems of government have evolved or been deliberately reformed to make it harder for the biggest wealth holders to grab or manipulate political power, as the complement to systems of law that stop political power holders from appropriating or illegally acquiring private wealth. Yet resentment of the ultra- rich, and their suspected political influence, has grown since the turn of the century. This can be easily and plausibly explained by a widening of inequality in the distributions of income and wealth, in many countries, as the real incomes and investment returns of the best- off inexorably rise (with no obvious connection to their productivity or management success), while the less well- off find their living standards frozen, or even falling, as prices rise ahead of incomes.