Stop Adding Up the Wealth of the Poor
1st January 2016
It’s the meme that refuses to die. It started, back in 2011, with the Waltons: six members of the family, we were repeatedly told, were worth as much as the bottom 30% of all Americans combined. I tried to address this silly stat back then, but now it’s gone global: back in January, Oxfam announced that the world’s 85 richest people had the same wealth as the bottom half of the global population. And now Forbes has come along to say that, actually, it’s not 85 people — it’s a mere 67.
Oxfam does a pretty bad job of footnoting its report, but I did manage to finally track down how it arrived at this conclusion. The 85 (or 67) number is easy: you just start at the top of the Forbes billionaires list, and start counting up the combined wealth until you reach $1.7 trillion. The harder question is: where does the $1.7 trillion number come from?
The answer is that it comes from a pair of tables in Credit Suisse’s 2013 Global Wealth Databook. First of all, you have to find the total wealth in the world, which you can find at the bottom of the fourth column on page 89: it’s $241 trillion. Then, you flick forwards to page 146, where you find the proportion of all global wealth held by each of the world’s income deciles. The top 10% have 86% of the wealth; the next 10% have 7.8%, and so on. Add up the bottom five deciles, and you get 0.7% (not 0.71%, which is the number in the Oxfam report; I have no idea where that extra basis point came from). And if you multiply $241 trillion by 0.7%, you get $1.7 trillion.
Basically, another instance of the Aggregation Fallacy.