Easter Island, also known as Rapa Nui, is a small island of 63 square miles that is 2000 miles off the coast of Chile in the southeastern Pacific ocean. The nearest inhabited islands are 1300 and 1600 miles away. So Easter island provides a natural experiment in history. Polynesian people most likely settled on Easter Island sometime between 700 and 1100, and created a thriving culture as can be seen by the island's many huge stone moai and other artifacts. The Easter Island population at it’s peak in 1600 AD was approximately 15,000. By the time the first Europeans arrived by ship in 1722, the island’s population had dropped to approximately 2500. What had happened over 100 years that dramatically reduced the island’s population?
Archeological record shows that at the time of the initial settlement the island was home to many species of trees, including at least three species which grew up to 15 metres (49 ft) or more, as well as at least six species of native land birds. A major factor that contributed to the extinction of multiple plant species (including the trees) was the introduction of the Polynesian rat. Studies by paleobotanists have shown rats can dramatically affect the reproduction of vegetation in an ecosystem. In the case of Rapa Nui, recovered plant shell seeds showed markings of being gnawed on by rats. Barbara A. West wrote, "Sometime before the arrival of Europeans on Easter Island, the Rapanui experienced a tremendous upheaval in their social system brought about by a change in their island's ecology... By the time of European arrival in 1722, the island's population had dropped to 2,000–3,000 from a high of approximately 15,000 just a century earlier."
By the time of European arrival in 1722, 21 species of trees and all species of land birds became extinct through some combination of overharvesting/overhunting and rat predation. The island was largely deforested, a contributing factor perhaps also being the hollowing out of large trees as boats, and it did not have any trees more than 10 feet tall. Loss of large trees meant that residents were no longer able to build seaworthy vessels, significantly diminishing their fishing abilities. Another theory regarding the deforestation that caused such ecological and social damage was that the trees were used as rollers to move the 100s of moai statues to their place of erection from the quarry at Rano Raraku. Deforestation also affected agricultural production on Rapa Nui. At first, the native tropical forests provided ideal shade cover for soil. But with much of the native forest being destroyed, with no shade the topsoil eroded causing a sharp decline in agricultural production. This was further exacerbated by the loss of land birds and the collapse in seabird populations as a potential source of food.
Overpopulation with extreme deforestation that lead to the inability to build boats for fishing, the degradation of the soil for farming, the extinction of land birds and the collapse of seabird populations from overhunting along with the impact of Polynesian rats, are thought to have been the main causes for the significant decline in the island population. The inhabitants unknowingly over generations depleted and degraded their limited resources on the island which lead to a significant decrease in population.
Jared Diamond in his book titled Natural Experiments of History compares the history and outcome of the island of Hispaniola as was first discovered by Columbus in 1492. Hispaniola now consists of an island with a border down the middle, with Haiti on the western side, and the Dominican Republic on the eastern side. In 2016 Haiti had a gross domestic product per capita of $739 – that’s the total of gross domestic production per year divided by the number of inhabitants, $739 per person. The Dominican Republic in 2016 had a gross domestic product per capita of $6722 - total of gross domestic production per year divided by number of inhabitants - $6722 per person. The GDP per person of the Dominican Republic is 9 times that of Haiti, but the countries occupy opposite sides of the same island, so why is there such a different in GDP per capita? The answer lies in looking at Hispaniola’s natural experiment in history. The eastern side of Hispaniola (Dominican Republic) now is green and forested while the western side (Haiti) is brown and treeless. The Dominican Republic receives most of the rain from the storms coming in from the east, leaving less to make it over the mountain to Haiti. Issues in addition to this geological factor significantly contributed to the present difference in GDP per capita. Let’s look at the political history of these countries. The eastern part of Hispaniola in 1496 was colonized by the Spanish establishing the capital in Santa Domingo. The western side was settled by the French participating in the slave trade. Two centuries later in 1697 Spain granted France the Western side of the island and a permanent boarder was established in 1777. The economy on the Western side of Hispaniola under French rule was still primarily based on the slave trade, with 85 percent of the population being slaves. The Eastern side under Spain had 10-15 percent of the population as slaves. There were 500,000 slaves in Western Hispaniola and 15,000 to 30,000 in the Eastern side. The slave economy on the western side lead to a dense population while the French in power cut down trees and shipped the timber back to France. This lead to the deforestation of the western side which resulted in erosion, decreased soil fertility and the general degradation of the land. Such degradation did not take place on the eastern side. The Haitian slaves also developed their own Creole language which would further isolate them from their neighbors.
Regarding Haitans and Domincans during this time period, Michael Shermer stated things rather well in The Believing Brain: Haitians and Dominicans gained their independence in the early 19th century. Haiti’s slave revolts during this time were violent, and France’s response to try and keep order caused the Haitian’s to deeply dislike and distrust the French and the Europeans in general. The Haitians wanted nothing to do with the French and Europeans regarding future trade and investments, imports and exports, immigration or emigration, and so they did not benefit economically from these factors. By contrast, Dominican independence was relatively non-violent, and it shuttled back and forth for decades between independence and control by Spain, which in 1865 decided that it did not want the territory. Throughout this period the Dominican spoke Spanish, develop exports, traded with European countries, attracted European investors and immigrants from all over Europe who helped build a vibrant economy.
One can see that from 1496 through the 1800s the social and economic conditions of the inhabitants on different sides of the same island were the primary cause of the different social outcomes of those inhabitants to this day – now those in Haiti have a GDP per person of $739 and those in the Dominican Republic one of $6722.
Another example of the results of a natural experiment in history is the comparison of North and South Korea. Korea was ruled by Japan from 1910 until the closing days of World War II. In August 1945, the Soviet Union declared war on Imperial Japan, and as a result of an agreement with the United States, liberated Korea north of the 38th parallel. U.S. forces subsequently moved into the south. By 1948, as a product of the Cold War between the Soviet Union and the United States, Korea was split into two regions, with separate governments. Both claimed to be the legitimate government of all of Korea, and neither accepted the 38th parallel border as permanent. The conflict escalated into open warfare when North Korean forces—supported by the Soviet Union and China—moved into the south on June 25, 1950. On June 27, the United Nations Security Council authorized the formation and dispatch of UN forces to Korea to repel what was recognized as a North Korean invasion. Twenty-one countries of the United Nations eventually contributed to the UN force, with the United States providing 88% of the UN's military personnel.
After the first two months of war, South Korean and U.S. forces rapidly dispatched to Korea were on the point of defeat, forced back to a small area in the south known as the Pusan Perimeter. In September 1950, an amphibious UN counter-offensive was launched at Incheon, and cut off many North Korean troops. Those who escaped envelopment and capture were forced back north. UN forces rapidly approached the Yalu river - the border with China—but in October 1950, mass Chinese forces crossed the Yalu and entered the war. The surprise Chinese intervention triggered a retreat of UN forces which continued until mid 1951.
After these reversals of fortune, which saw Soeul change hands four times, the last two years of fighting became a war of attrition, with the front line close to the 38th parallel. The fighting ended on 27 July 1953, when an armstice was signed. The agreement created the Korean Demilitarized Zone to separate North and South Korea, and allowed the return of prisoners. However, no peace treaty has been signed, and the two Koreas are technically still at war.
Since the formation of North and South Korea, dictatorship and poverty prevail in North Korea and democracy and a vibrant economy prevail in South Korea. As of 2014 the GDP per person in north Korea was $583, in South Korea in 2016 the GDP per person was $27,538. That is a whopping 47 times difference in standard of living! What causes these differences on the Korean peninsula? Difference in the social, economic and political aspects of society were largely determined by the inhabitants of each area, with the large influence of foreign powers like the USA on south Korea and China and Russia on North Korea also having an influence after the Korean War.
As can be seen in these three examples of natural experiments of history, social, environmental, economic and political aspects of a society can have a tremendous effect on the future of that society. As citizens in a Democratic Republic deciding the future of the USA, we should keep these natural experiments in mind when voting for our representatives in office to make sure they are leading the country in the right direction. If we are not knowledgeable citizens ourselves when exercising our right to vote in our Democratic Republic, we risk losing the role as the most powerful country in the world and theoretically in the long term risk going in the direction of Easter Island, Haiti and North Korea.
The Believing Brain: Michael Shermer, 2011, St. Martin’s Press
Natural Experiments of History: Jarod Diamond and James Robinson, Belknap Press
Sapiens – A Brief History of Humankind: Yuval Noah Harari, 2015, HarperCollins Publishers