At first sight, income inequality and poverty are completely different things. Poverty is clearly a human rights issue, while income inequality is clearly not, at least not directly (it can have an impact on some human rights). Income inequality is a relative indicator, not an absolute one, and is, for this reason, claimed to be not about poverty at all. Poverty, it is said, is about absolute deprivation and is a lack of the resources necessary to satisfy certain basic needs. Income inequality just describes the unequal possession of resources, basic or otherwise. And indeed, it’s possible to imagine a very rich society in which no one is poor in the sense of lacking basic resources, but in which the distribution of resources is very unequal. Vice versa, there may be countries in which everyone is (almost) equally poor.
However, if we compare countries, we see that the more unequal a society, the larger the numbers of people suffering from poverty. Does that mean that high income inequality leads to more poverty? Not necessarily. That would probably be the case if we saw that a country’s poverty rate grows with increasing inequality. But that doesn’t happen:
If we look across the rich nations, it turns out that there is no relationship between changes in income inequality and changes in the absolute incomes of low-end households. The reason is that income growth for poor households has come almost entirely via increases in net government transfers, and the degree to which governments have increased transfers seems to have been unaffected by changes in income inequality. …
In some countries with little or no rise in income inequality, such as Sweden, government transfers increased and so did the incomes of poor households. In others, such as Germany, transfers and the incomes of low-end households did not increase.
Among nations with sharp increases in top-heavy inequality, we observe a similar disjunction. Here the U.S. and the U.K. offer an especially revealing contrast. The top 1%’s income share soared in both countries, and through the mid-1990s poor households made little progress … But over the next decade low-end American households advanced only slightly, whereas their British counterparts experienced sizable gains [thanks to the Labour government, FS]. (source)
So, in other words, there are countries with soaring inequality that still manage to make the poor better off in absolute terms (not in relative terms obviously) through redistribution. Other countries that witness the same evolution of inequality don’t make their poor better off. And trickle down also doesn’t seem to work, by the way. Vice versa, the less unequal countries also differ in the way they treat the poor. Income inequality doesn’t produce poverty because it doesn’t affect the welfare state.
It’s often argued that income inequality not only fails to produce poverty but actually helps to reduce it. That argument goes something like this. High levels of income inequality – and therefore high wages at the top – are necessary for economic growth. If the top economic performers are allowed to earn very high wages, they will have an incentive to produce and innovate. That will lead to economic growth, which will in turn, through a trickle down mechanism, benefit everyone, including the poor and those earning very little.
However, from the quote above it follows that it’s government transfers rather than automatic mechanisms that have helped the poor during the last decades of increasing inequality. If inequality by itself would reduce poverty, these government transfers would not have been necessary. An increase in income inequality by itself does not improve low-end incomes, as is shown by the example of the US.
And even if it could be shown that rising inequality pushes up the absolute income of the poorest, there are other reasons to object to inequality (such as this for example).