In January 1963, Warren Buffett included the following impish observation in his letter to his investment partners. “I have it from unreliable sources that the cost of the voyage Isabella underwrote for Columbus was approximately $30,000.”
Unreliable indeed; there was no dollar in 1492. But we get the gist. Buffett goes on to observe that while the voyage could be considered “at least a moderately successful utilisation of venture capital”, if Queen Isabella had instead invested the $30,000 in something yielding 4 per cent compound interest, the invested sum would have risen to $2tn by 1962. For her inheritors’ sake, perhaps Isabella should have said no to Columbus and simply found the 15th-century equivalent of a passive index fund instead.
Buffett’s thought experiment returned to me as I browsed through the latest list of billionaires from Forbes. None of the leading players had achieved their position by the simple accumulation of family wealth over generations. The top five — Bill Gates, Amancio Ortega, Buffett, Carlos Slim and Jeff Bezos — are all entrepreneurs of one form or another. According to economists Caroline Freund and Sarah Oliver, the proportion of billionaires who inherited their fortunes has fallen from 55 per cent two decades ago to 30 per cent today.
Is this absence of old-money trillionaires because Buffett’s 4 per cent compound interest was unavailable to the wealthy and powerful of pre-industrial Europe? Hardly. If anything, 4 per cent is conservative. According to Thomas Piketty’s bestselling book Capital in the Twenty-First Century (2013), the real rate of return on capital, after taxes and capital losses, was 4.5 per cent in the 16th and 17th centuries, then 5 per cent until 1913. Although it fell sharply between the wars, the effective average rate of return was very nearly 4.3 per cent across the five centuries. At that rate, $30,000 invested in 1492 would be worth $110tn today.
Not to get too technical, but $110tn is a lot of money. It’s more than 1,000 times the wealth of the richest man in the world, Bill Gates. It’s 17 times the total wealth of the 1,810 billionaires on the Forbes list — or, alternatively, nearly half the household wealth of every citizen on the planet. (According to Credit Suisse’s Global Wealth Report, total global household wealth is $250tn.) Queen Isabella’s investment advisers apparently let her down. Patient, conservative investments would have left her heir today with a fortune to tower over every modern plutocrat.
All this brought to mind Piketty’s “r>g”, a mathematical expression so celebrated that people started putting it on T-shirts. It describes a situation where “r” (the rate of return on capital) exceeds “g” (the growth rate of the economy as a whole). That is a situation that described most of human history, but notably not the 20th century, when growth rates soared while capital had a tendency to be nationalised, confiscated or reduced to rubble.
“r>g” is significant because if capital is reinvested and grows faster than the economy, it will tend to loom larger in economic activity. And since capital is more unequally distributed than labour income, “r>g” may describe a society of increasingly entrenched privilege, where wealth and power steadily accrue in the hands of heirs.
This is a fascinating, and worrying, possibility. But it is a poor description of the modern world. For one thing, when billionaires divide their inheritance, mere procreation can be a social equaliser. Historically, the great houses of Europe intermarried and concentrated wealth in the hands of a single heir. (No wonder: one of Queen Isabella’s grandsons, Ferdinand I, had 15 children.) But these days, disinheriting daughters and second sons is out of fashion. (That said, “assortative mating”, the tendency of educated people to marry each other, is back and may explain more about rising income inequality than we tend to realise.)
Another thing: the rich do not simply wallow in money vaults like Scrooge McDuck. They spend. According to Harvard economist Greg Mankiw: “A plausible estimate of the marginal propensity to consume out of wealth, based on both theory and empirical evidence, is about 3 per cent.” Instead of 4.3 per cent, then, wealth compounds at 1.3 per cent after allowing for this spending. Five centuries of compound interest at 1.3 per cent turns $30,000 into about $25m, a fine inheritance indeed but not the kind of money that will get you near the Forbes list.
Of course, inherited privilege shapes our societies not only among the plutocracy but down in the rolling foothills of English middle-class wealth. There, economic destiny is increasingly governed by whether your parents bought a house in the right place at the right time — and by the UK government’s astonishing abolition of inheritance tax on family homes.
But whether mega-wealth in the 21st century will be driven by the patient accumulation of rents on capital, rather than the disruptive entrepreneurship of the late 20th century, remains to be seen. After all, long-term real interest rates in advanced economies have fallen fairly steadily from 4 to 5 per cent three decades ago to nothing at all today. You don’t need to be Warren Buffett to figure out that if you want to get rich by accumulating compound interest of zero, you’ll be waiting a long time.
Tim Harford is the author of ‘The Undercover Economist Strikes Back’.
我在浏览《福布斯》(Forbes)最新亿万富翁排行榜时，回想起了巴菲特的这一“思想实验”。排在榜单前面的亿万富翁都不是通过简单的一代又一代人累积家族财富而取得现在的地位的。列在该排行榜前5位的是比尔?盖茨(Bill Gates)、阿曼西奧?奧特加(Amancio Ortega)、巴菲特、卡洛斯?斯利姆(Carlos Slim)和杰夫?贝索斯(Jeff Bezos)，他们都是某种形式的企业家。经济学家卡洛琳?弗洛恩德(Caroline Freund)和莎拉?奥利弗(Sarah Oliver)表示，依靠继承财富上榜的亿万富翁数量已从20年前的55%降至现在的30%。
通过继承财富上榜的亿万富翁寥寥无几，是否是因为在工业时代以前的欧洲，富人和有权势的人无法得到巴菲特所说的4%的复利？绝非如此。4%甚至是个保守数字。托马斯?皮凯蒂(Thomas Piketty)所著的畅销书《21世纪资本论》(Capital in the Twenty-First Century)（2013年出版）称，计入税收和资本损失后，16和17世纪的实际资本回报率为4.5%，接着是5%，直到1913年。尽管在两次世界大战之间资本回报率曾大幅下滑，但5个世纪以来的平均实际回报率非常接近4.3%。按照这个回报率，如果在1492年投资3万美元，现在的价值将达到110万亿美元。
我不想搞得太专业，但110万亿美元是一大笔钱。它是全球首富比尔?盖茨财富总额的1000多倍，是《福布斯》排行榜上1810位亿万富翁财富总额的17倍，或者是全球所有公民家庭财富的近一半。（根据瑞信(Credit Suisse)的《全球财富报告》(Global Wealth Report)，全球家庭总财富为250万亿美元。）伊莎贝拉女王的投资顾问显然辜负了她。耐心保守的投资将让她现在的继承人坐拥超过任何一位现代富豪的财富。
另一点：富人不会像唐老鸭的舅舅史高治?麦克老鸭(Scrooge McDuck)那样钻到钱眼里。他们会消费。哈佛大学(Harvard)经济学家格里高利?曼昆(Greg Mankiw)称：“根据理论和经验证据，财富的边际消费倾向的合理估值约为3%。”若刨除这种消费，则财富的复利为1.3%，而不是4.3%。按照1.3%的复利，3万美元经过5个世纪会变成大约2500万美元，这确实也是一笔丰厚的遗产，但不会让你登上《福布斯》排行榜。
本文作者著有《卧底经济学家反击战》(The Undercover Economist Strikes Back)一书