Two “L” shaped graphs highlight the extraordinary changes in human prosperity over the last twelve thousand years. After millennia of infant mortality rates of 200-300 per 1,000 and life expectancy at birth of 20-30 years, most people today are living in nations where infant mortality rates are dropping below 50, on their way to the single digit levels of the West. Global life expectancy is pushing 70 years. These “L” shaped developments contribute to the development of yet another “L” shaped curve. Look at this chart of world population:
We can get a better sense of population growth if we break the chart into two segments:
From 10,000 BCE to 5000 BCE, the global population increased from about 4 million to 5 million. Beginning in the fifth millennium, the plow was invented, irrigation began, and cities emerged. There was an up turn in population during the Greco-Roman era beginning in the middle of the first millennium BCE. Much slower growth followed in the third through eighth centuries CE. Population fluctuated until after the major European plague in the mid-1300s, after which population resumed an upward trajectory, particularly accelerating in the seventeenth century.
Many have attributed the population explosion of recent centuries to the Industrial Revolution but clearly its impetus predated the Industrial Revolution by one or two centuries. Economist Robert Fogel attributes this population growth to what he calls the Second Agricultural Revolution beginning in the seventeenth century (the First Agricultural Revolution beginning around 9000 BCE with the discovery of farming techniques.) The Second Agricultural Revolution, starting in Europe, involved a combination of improved crop rotation methods, better planting and cultivation techniques, new technology, and improved storage and distribution methods. Beginning in the early nineteenth century (c. 1820) the Industrial Revolution built upon the gains from agricultural advancements.
Robert Fogel calls the phenomenon we have experienced in recent centuries “technophysio evolution.” Technology improved agricultural to the point that vast numbers of people could eat beyond mere subsistence levels and live healthier and more productive lives. Better agriculture production also required fewer workers freeing up labor for other pursuits. These other pursuits included pursuit of new technologies that both bettered people’s lives and further improved agricultural production. Thus, a cycle of technophysio evolution was set in motion.
Next we look at what is known as the Demographic Transition Model
