Tracking levels of world inequality can pose a variety of statistical challenges for researchers. Different nations, for starters, tally income and wealth in different ways, and some nations barely tally reliable stats at all. But researchers worldwide are increasingly taking on these challenges.
In 2006, scholars with the United Nations University’s World Institute for Development Economics Research published the first paper to tally, for the entire world, all the major elements of household wealth, everything from financial assets and debts to land, homes, and other tangible property. This research, based on year 2000 data, found that the richest 1 percent of world adults, individuals worth at least $514,512, owned 39.9 percent of the world’s household wealth, a total greater than the wealth of the world’s poorest 95 percent, those adults worth under $150,145.
Luxembourg Income Study
Scholars connected with the Luxembourg Income Study have created a cross-national data archive, for both income and wealth, that seeks to address the challenges of collecting comparable data on world inequality. But this project remains more a basic resource for researchers than a source of information for the general public.
The World Top Incomes Database
This interactive online initiative from the Paris School of Economics and three partner groups offers scholars and the general public alike a more accessible window into the incomes of the globe’s most affluent. Visitors to the site can graphically compare, over time, the income shares of the wealthy in 23 different nations. And the comparisons enabled can drill all the way to a nation’s most affluent 0.01 percent.
In more recent years, a number of global financial industry firms have been releasing their own annual calculations on worldwide wealth concentration. Among these efforts: the World Wealth Report from Capgemini and RBC Wealth Management, the Global Wealth report from the Boston Consulting Group, the World Ultra Wealth Report from the Singapore-based Wealth-X and the Swiss bank UBS, the Global Wealth Report from the German bank Allianz, and the Wealth Report from the Knight Frank property management group.
Each of these reports takes a slightly different approach to tallying up concentrated wealth. Capgemini and RBC, for instance, look at “high net worth individuals,” those affluents who hold personal fortunes worth at least $1 million, excluding primary residences, collectibles, and consumer goods. The Boston Consulting Group analyze millionaire households. Wealth-X and UBS researchers place their statistical emphasis on deep pockets worth at least $30 million.
The most ambitious of all the annual financial industry wealth reports comes out of the Credit Suisse Research Institute in Zurich. Credit Suisse’s Global Wealth Report estimates the net worth — both financial and “real” assets like housing — for all the world’s adults. In 2014, Credit Suisse researchers estimate, individuals holding over $1 million in wealth — the richest 0.7 percent of adults globally — held 44 percent of global net worth.
The best estimates for wealth’s concentration at the global economic summit come from Forbes magazine. Forbes annually tallies the fortunes of the world’s billionaires.
As of February 2014, Forbes reported last year, the world hosted 1,645 billionaires, over double the 793 billionaires Forbes counted in 2009, at the depth of the Great Recession. These 1,645 billionaires together hold $6.4 trillion in wealth.
The 3.3 billion adults in the world with less than $10,000 to their name, Credit Suisse noted in October 2014, together hold $7.6 trillion in net worth.
The Global Big Picture
Is the world, as a whole, growing more or less unequal? This simple question has no simple answer.
Branko Milanovic, a senior scholar with the Luxembourg Income Survey now at the City University of New York’s Graduate Center, has done the world’s most rigorous research on the global income inequality picture. His latest research, published in December 2014, carries the theme “national vices, global virtue.”
Inequality within nations is increasing, Milanovic notes, but inequality worldwide seems to be slightly decreasing as middle classes emerge in China and India and the incomes of typical families in the United States and other rich countries stagnate and even, after inflation, decrease. But this slight worldwide decrease in overall inequality, Milanovich cautions, may be somewhat illusory since available national data regularly underestimate top 1 percent incomes and global tax havens conceal still more income at the economic summit.