Graph of the week
From Axios
The wealth of the world’s billionaires rose by $1.4 trillion in 2017, the largest annual increase ever.
The details: Nearly all of that increase was driven by the Asia-Pacific region, and specifically China, where billionaire wealth rose 39%.
The graph is not well designed for illustrating the claim about billionaires: in a stacked bar chart like this it is easy to compare the first level, the sum of the first two, and the sum of all three, but not the top level. If the chart had been stacked the other way up it would be more obvious that it doesn’t seem to go along with the claim.
Measuring the height of the bars in MacOS Preview (because it’s not possible to read the graph to high enough precision) I get 35 pixels increase in the Asia-Pacific region and 46 in the rest of the world, so the growth in the Asia-Pacific region actually is less than half the total growth. Estimating the total growth by counting pixels does agree with the $1.4 trillion total, so what has gone wrong?
Clicking through to the UBS/PwC press release gives a bit more detail:
Chinese billionaires increased in number to 373 in 2017 from 318 in 2016 and their wealth rose by 39 percent to USD 1.12 trillion
So, the net increase in total wealth for Chinese billionaires is about $0.44 trillion. That hardly qualifies as “nearly all” of the increase for the Asia-Pacific region, let alone for the world
The original source is the the UBS/PwC Billionaires report. Their graph is better (apart maybe from the second y-axis). Not only is it the right way up for looking at increases in Asia vs the rest of the world, but it’s got tick marks on the right-hand axis where they’re actually useful. And it shows some historical context.
Normally I wouldn’t go to this much effort for a business news item — but the Axios Edge newsletter where I read this is edited by Felix Salmon, who is usually better at the difference between “nearly all” and “nearly half”
P.S. Yes, I did think of titling this post Crazy Rich Asians. No, I’m not sorry I didn’t.
Thomas Lumley (@tslumley) is Professor of Biostatistics at the University of Auckland. His research interests include semiparametric models, survey sampling, statistical computing, foundations of statistics, and whatever methodological problems his medical collaborators come up with. He also blogs at Biased and Inefficient See all posts by Thomas Lumley »