August 13th, 2020
The basic facts regarding Easter Island are no longer in serious dispute. It is, however, important to understand why Easter Island suffered an internally generated collapse based on resource overuse. The real question is whether Easter Island is an unusual and isolated case or whether it is a cautionary tale for the modern world. It is therefore important to uncover any general principles that might be inferred from the Easter Island experience.
One important idea that might shed light on Easter Island derives from Malthusian population dynamics. Polynesian societies (along with virtually all other societies at comparable stages of development) were Malthusian in the sense that fertility was positively related to consumption (or real income) and mortality was negatively related to consumption. Correspondingly, in times of increasing hardship, fertility would decrease and mortality would increase. Depending on the precise responsiveness of fertility and mortality to real income (or food supply), and on other aspects of the environment, it is possible for Malthusian populations to ‘‘overshoot.’’ Such populations would tend to increase too rapidly to be sustained, leading to an ultimate population "crash" enforced by some of the more unpleasant instruments of mortality, such as disease, starvation, and violent conflict. This possible feature of Malthusian models led subsequent readers of economist Thomas Malthus to refer to economics as the ‘‘dismal science.’’