Natural Experiments of History

2018/08/23

When I was a child, I used to look at photos of the Moai statues left on Easter Island in the Pacific Ocean and wonder about them. Who made such massive things, and where did those people disappear to? There were wild theories that the island was part of the legendary continent of Mu, or that aliens had created the giant statues, but in reality, the former inhabitants of this island were Polynesians. Furthermore, although Melanesians and Micronesians share the same roots and settled on various islands across the Pacific, they followed different fates. Why was it that only Easter Island fell into ruin?

On the other hand, history is full of "what ifs" in addition to these "whys." For example, if the slave trade centered on the African continent had never existed, would African nations be wealthier today than they are now?

This book, "Natural Experiments of History," is a collection of papers compiled by editors Jared Diamond (author of "Collapse") and James Robinson (author of "Why Nations Fail") that scientifically tackle historical mysteries of "why" and "what if" using the method of natural experiments. "Natural experiment" might be an unfamiliar term, but here, it involves comparing subjects that share many similarities but differ significantly in specific areas to uncover hidden causal relationships. Unlike science, history cannot conduct experiments in a controlled environment; instead, natural experiments focus on quantitative data and measurements, carefully building evidence. It is surprising to see how clearly the reasons for Easter Island's ruin and the fate of the African continent had the slave trade not occurred emerge through this process.

The book also covers various interesting themes from different eras, such as why massive numbers of immigrants flocked to the Americas, why the development of banking systems differed by country, the legacy left by British rule in India, and the impact of the French Revolution on Europe. It is a valuable volume that teaches us how future developments can differ greatly due to slight variations even in similar environments, and that we can scientifically clarify what those slight differences are without needing a time machine.

Natural Experiments of History

Edited by Jared Diamond and James A. Robinson, Translated by Eri Kosaka

Keio University Press

320 pages, 2,800 yen (excluding tax)

*Affiliations and titles are those at the time of publication.