The right way to learn from Genghis Khan

Meaning:An apocryphal story is one that gets told and retold as fact even though it probably never happened — widely believed, never verified. The word comes from the Apocrypha, a set of books left out of the official Bible because their authenticity was doubted, and it now covers everything from a famous quote nobody can trace to the tale that Einstein failed maths. Here it is doing careful work in a single word: the grisly Genghis line still turns up in leadership talks, and the writer repeats it while quietly warning that it may never have come out of his mouth.

Meaning:To ascribe a result to something is to name it as the cause — to assign the credit, or the blame, to a particular source. It usually carries a hint that this is a judgement rather than a settled fact, which is why art historians ascribe an unsigned painting to a particular artist and why you can ascribe a bad grade to a bad night's sleep. The whole argument of this article lives inside that word: Genghis would have ascribed his conquests to his own courage and horsemanship, while Jared Diamond ascribes them largely to twenty unusually rainy years on the Mongolian steppe.

Meaning:Belligerent means spoiling for a fight: aggressive, hostile, looking for the argument instead of a way around it. It comes from the Latin for waging war, and in its strict legal sense a belligerent is a country actually at war — which is why news reports call the two sides in a conflict "the belligerents" — but in everyday use it has slid down from nations to describe a single person's manner. The article uses the everyday sense to land an uncomfortable point: plenty of voters want a leader who picks fights, even though refusing to pick fights with his neighbours is one of the things that made Seretse Khama work.

You want to know whether the person in charge actually matters. The clean way to find out would be to run America twice — once with Donald Trump, once with Kamala Harris — and compare the results. Obviously you cannot. That is the permanent frustration of the social sciences: the experiment you want is the one nobody will let you run.

The workaround that economists, political scientists and epidemiologists use is called a natural experiment. You go hunting for a moment when the world, by accident, did the sorting for you — when who got the "treatment" and who did not was settled by something unconnected to the thing you are studying. Here the accident is death. A leader having a fatal heart attack has nothing to do with whether the economy was about to boom or slump; it is about as close to a coin flip as history offers. So you line up the 183 heads of government who died or were forced out between 1875 and 2004, measure growth before and after each one, and whatever pattern shows up is hard to explain away.

The pattern was subtle and worth sitting with. Average growth after a leader died was no different from normal — but the spread blew wide open: growth became far more likely to swing sharply up or sharply down. That is exactly the fingerprint you would expect if the individual really does matter. When a hopeless leader dies, things get better; when a capable one dies, things get worse; average those two together and they cancel out, which is why the average alone would have told you the opposite of the truth.

The catch is that the accident has to be genuinely unrelated to what you are measuring — if leaders tended to die because of economic crises, the whole method collapses. So whenever you meet a study claiming that X causes Y out in the real world, ask what did the sorting, and whether that same something could have produced Y all on its own.

At independence in 1966 Botswana had seven miles of paved road and 22 university graduates. Then it struck diamonds under one tribe's land — and across post-colonial Africa, that sentence usually ends in a war. It did not, because of a distinction in property law that most people never think about.

Owning the surface of a piece of land and owning the minerals underneath it are two separate rights, and they can sit with two different owners. Buy a house in Texas and you may own the dirt, the lawn and the building while an oil company owns everything below your feet — the right to drill and the right to the money that comes up. That split is what "mineral rights" means, and every country settles it differently. In most of the world, Britain and nearly all of Africa included, the valuable material underground belongs to the state by default; across much of the United States it belongs to whoever owns the surface, which is why an American farmer can sign a drilling lease and collect royalty cheques and a Nigerian villager cannot.

Seretse Khama was in the rare position of getting to choose. The diamonds lay under the land of his own tribe, so he could have made his own people — and himself — extraordinarily rich and called it fair. He handed the rights to the state instead. That did two things at once: the diamond money paid for roads and schools for the whole country, and no group had a prize sitting under its feet worth fighting anyone else for.

Keep this in your pocket for every story about oil, lithium, gold or deep-sea mining. The fight is almost never about who found the stuff. It is about who was already legally entitled to whatever lies underneath.