Profits, Prophets, Coaches and Kings by Jared Diamond review – how to change the course of history

Early in this book, Jared Diamond proudly introduces “what I term ‘the Hamlet test’”, which helps decide whether prominent individuals really make a difference, or whether others might have done just as well. Among William Shakespeare’s contemporaries on the Elizabethan stage, he explains, were “Ben Jonson, Christopher Marlowe and John Webster. But not even their best plays remotely approach in quality Hamlet and Shakespeare’s other masterpieces.” It follows, for Diamond, that Shakespeare was indeed “uniquely talented”: “We can be confident that no Elizabethan other than Shakespeare could have written a masterpiece like Hamlet if Shakespeare hadn’t done so.”

One obvious problem with this is that Marlowe was stabbed to death in a pub in Deptford in 1593 at the age of 29, having already written the absolute bangers Doctor Faustus and Tamburlaine, as well as – so it is now thought – co-writing the Henry VI trilogy with the up-and-coming Shakespeare. Shakespeare himself did not begin to compose his major tragedies, including Hamlet, until he was a decade older. So we can’t rule out the possibility that, had Marlowe lived another 10 years, he would have matched or even exceeded his colleague’s genius. Scholars widely agree that Hamlet and Shakespeare’s other masterpieces were possible only thanks to the outsized influence of Marlowe.

But Diamond is not interested in what literary scholars think, and is confident that his “Hamlet test” is a fine intellectual novelty. Indeed, he is not much interested in what scholars of history, or ethics, or business studies think either, because this is one of those books that pretends the subject is one nobody has thought rigorously about before.

Diamond argues persuasively that at least the first president of independent Botswana, Seretse Khama, passes the Hamlet test: he made the country safe for democracy by “gut[ting] the power of the traditional chiefs”, for example, but only he could do that, “because he was the most powerful chief”. Much later in the book, we happily agree that only a particular couple of very rich Californians could have invented the pomegranate-juice industry – or, to generalise the lesson, you have to have lots of wealth already to go into a business with very high up-front costs and a lengthy startup period. No shit, Sherlock, as the reader will have cause to exclaim at numerous points throughout the book.

As Diamond skips from politics to sport to business, the main interest is supplied by his concentration on the method of “natural experiments”: the statistical comparison of similar past events. In the 1990s, economists David Card and Alan Krueger analysed fast-food joints close together on either side of a state line: New Jersey had just passed a law to increase its minimum wage, while its neighbour Pennsylvania had not. In two celebrated papers, they proved that the increase in the minimum wage led to higher employment, contrary to the received economic wisdom. Similar analyses suggest that CEOs are responsible for between 6% and 29% of the variation in a company’s earnings, while sports coaches are on the hook for at most about 30% of a team’s performance. (Here I thought I could hear Thomas Tuchel breathing a sigh of relief.)

Analysis of natural experiments is a fun tool, but obviously harder to make work the further you travel from objectively quantifiable things such as money or win/loss records. One Diamond cites used the amount of parking fines incurred by national staff at the UN’s New York headquarters as a proxy for their countries’ level of political corruption, which is already a stretch. Another took the preponderance of cousin marriage as a proxy for lower IQ (because of inbreeding effects), and so found that stupider European monarchs over the past four centuries were less successful in expanding their territory. (Not supplied here is any argument that expanding your territory is always good.)

One of Diamond’s more striking examples also betrays some unreliability on his part. He writes that in their 2009 paper Hit or Miss? The Effect of Assassinations on Institutions and War, Benjamin F Jones and Benjamin A Olken showed that successful assassinations don’t make much difference to the outbreak of wars, and concludes that the killing of Franz Ferdinand didn’t cause the first world war. But the study itself explicitly cautions against that inference: Ferdinand is not included in their data, since he was not the “leader” of the Austro-Hungarian empire. Diamond also neglects to mention that paper’s more interesting finding, which is that, in autocracies, assassination can help make a transition to democracy more likely.

The book ends by suggesting other questions that “natural experiments” of this kind might address, on the implicit grounds that only quantitative methods from the social sciences can provide satisfactory answers. One of them is “Under what circumstances do military leaders most make a difference?” On this topic, Diamond might have read with profit a book by a military historian, for example, Lawrence Freedman’s superbCommand. But from this book’s Olympian perspective, subject-matter experts in military affairs are as invisible as those in literary history.