Scales continue to tip in the rich's favor the world around.
Income inequality -- the gap between a society's richest members and its poorest -- is rising not only in the United States but in most of the world's major economies, according to a new report from the Organization for Economic Cooperation and Development.
Since 1985, income inequality has grown more pronounced in 17 of the 22 countries for which the OECD has long-term data, including Mexico, Italy, Japan, Australia, Canada and the United Kingdom.
The OECD's report suggests an explanation for why the Occupy Wall Street movement has grown from a single protest site in New York's Zuccotti Park to a global phenomenon with hundreds of chapters in dozens of countries. Among other things, protesters in the Occupy movement say they oppose the concentration of wealth in the hands of fewer and fewer people.
In the United States, the incomes of the very highest earners have grown by leaps and bounds over the last quarter century, while remaining more or less flat for the vast majority of the population.
Comparable growth in the wealth gap has taken place in Germany, Finland, Israel, Sweden, Luxembourg and New Zealand, according to the OECD. Only five countries -- Greece, Turkey, France, Belgium and Hungary -- saw their levels of income inequality decline or remain constant.
Income inequality has been linked to a number of troubling economic trends, and some analysts believe the wealth gap is contributing to the slow rate of recovery for the global economy.
Earlier this year, a study in the newsletter of the International Monetary Fund suggested that a country is more likely to enjoy a sustained period of growth if it has a relatively equitable distribution of income -- meaning that for the wealthy, high-inequality nations named in the OECD report, bouncing back from the worldwide recession may be taking longer than it needs to.
Income inequality has also been cited as a catalyzing factor for a number of protest movements around the globe, including the riots in England this summer and the Arab Spring uprisings in the Middle East on which the Occupy Wall Street movement has been patterned.
An OECD press release notes that income inequality, besides affecting the wealthy member-nations of the organization, is also a major concern in many of the developing countries outside of it. The correlation between a nation's wealth gap and its poverty and social and political instability was suggested earlier this year, when The Atlantic published a world map color-coded by inequality. China, Brazil, Rwanda, Uganda, Cote d'Ivoire and Serbia all had high levels of income inequality -- as did the United States.