Different decades have been obsessed with different doomsdays. From the 1940s to the early 1960s, people worried especially about nuclear war. From the late 1960s on, fears of overpopulation and ecological doom came to the fore. John Brunner’s Stand on Zanzibar (1968) is still one of the best science fictional imaginings of a planet cracking apart under the stress of overpopulation, a richly detailed piece of world-building. Like all visions of the future, it reflects the time it was conceived in, carrying a sense that the cultural revolutions of the 60s were spinning out of control.
For non-fiction there was The Limits to Growth (1972). Here is Scenario 1 from the book, generated by a computer model of the interaction of population, resources, industry, food, and pollution. Fiddling with the model suggested that it would be very hard to avoid a massive collapse in one form or other. If the exhaustion of resources didn’t get you, pollution would do the job.
None of this is meant to suggest that we shouldn’t worry about our ecological future. Rather that we should be thankful that we’re now getting to be rich enough that we can worry less about immediate subsistence threats and more about distant dangers.
The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate.
Paul Ehrlich. The Population Bomb. 1968
Ironically, it was just around the time that Ehrlich wrote this that production of rice and wheat in India, the Philippines, and other countries was booming thanks to the Green Revolution – more productive plant varieties that could take advantage of fertilizer and pesticide inputs. It’s true, as Malthus pointed out long ago, that exponential population growth can eat up any conceivable increase in agricultural output. But the Green Revolution bought the world some breathing space until birth rates began to come down. It probably also eased some of the paranoia about food supply that played a part in two world wars, and the rural discontent that fueled earlier peasant revolutions.
Norman Borlaug, Green Revolution pioneer, awarded Nobel Peace Prize, 1970
Whoever makes two ears of corn, or two blades of grass to grow where only one grew before, deserves better of mankind … than the whole race of politicians put together.
Malthusianism does a pretty good job of capturing the facts of life for our species before the Industrial Revolution. For example, Malthus plus standard economics helps account for some of the historic differences between wheat and rice growing societies. And Darwinism suggests the reason why Malthusianism holds for living things in general: within a population, variants with a higher intrinsic rate of increase tend to replace those with a lower rate, even if the eventual outcome is overpopulation and misery for all. So the field of human behavioral ecology, based on the assumption that people try to maximize fitness, does pretty well in accounting for behavior in pre-modern societies.
But Malthusianism, and the assumption that people are fitness-maximizers, don’t work very well for modern societies. Even as life expectancies and standards of living have been increasing around the world, fertility rates have been declining, falling below replacement levels even in many less developed countries (rates remain high in Sub-Saharan Africa, although falling even there.) The United States mostly follows the general trend, with a long decline in fertility rates over several centuries.
And then there’s the Baby Boom: Birth rates in the United States went up dramatically following the Second World War, then reached a peak in 1957, and continued high into the early 1960s. Young people were marrying early, and having more children. Women were staying out of the workforce to take care of the kids.
Here are two popular theories of why the Baby Boom happened that don’t work:
Soldiers coming home. The return of soldiers from the Second World War contributed to an early spike in the birth rate (visible in the chart above as a peak in 1947). But the boom lasted too long to be mostly explained this way, and involved a big increase in the total number of babies born, not just people getting around to having babies that they’d put off having earlier.
Women squeezed out of the labor force. Increasing employment and educational opportunities for women are one of the long-term drivers of the demographic transition. So were these factors operating in reverse during the Baby Boom? The data clearly rule this out. Women’s wages actually rose rapidly during this period, and older women, with their child-rearing years mostly behind them, responded by entering the labor market in large numbers. In other words, employers were eager to hire women, but young women, at least, thought they had better things to do.
A more promising account comes from Richard Easterlin. (But see here for some doubts about Easterlin, and some alternative theories involving improvements in household technology, and more affordable housing.) Easterlin proposes that the Boom happened because young men encountered an exceptionally favorable labor market, resulting from the conjunction of several factors. (1) Birth rates fell to low levels during the Great Depression, naturally enough. As a result, twenty years on, employers faced a shortage of native-born young men looking for entry level jobs. (2) In the nineteenth century, periods of high demand for labor in the United States saw increases in immigration; levels of immigration tracked the business cycle. But in the mid-twentieth century, legal restrictions made it difficult to increase the supply of labor through immigration. Employers instead had to offer higher wages for entry level workers. Young men felt they were doing well enough – both absolutely and relative to the older generation – to get an early start on marrying, and to support their wives while raising bigger families.
The Baby Boom would be its own undoing however. As the earliest Boomers grew up and started to crowd the job market and the universities, “The Sixties” took off.
The Taiping rebellion in China began in 1850 and was finally put down in 1864. It was led by a former school teacher who discovered, after repeatedly failing his civil service exams, that he was the younger brother of Jesus Christ, destined to bring China over to his own brand of Christianity.
The rebellion was by far the most destructive conflict in the nineteenth century. It illustrates a general characteristic of Chinese history: Chinese wars were fewer but more destructive than European ones. China was unified for most of the past two millennia, governed by dynasties which established peace for long periods of time, among a huge population, over a vast area. But when things fell apart in China, whether from invasions (usually involving steppe nomads) or internal rebellions, vast numbers of people died. Here’s a chart comparing estimated numbers of war deaths for major wars Europe (red) and China (blue) between 1 and 1800 CE. China’s population during this period was somewhat less than twice that of Europe, so even per capita, China’s military catastrophes were more demographically catastrophic than Europe’s.
The Taiping rebellion comes too late to show up on the chart, but cost the lives of about 20 million people.
Pangaea reunited. In the century after 1492, West Europeans mastered the winds and currents of the world’s oceans. The shock to the rest of the world would be comparable in some ways to the earlier shock resulting from the spread of nomadism on the Eurasian steppes. In the Americas, the immediate results were devastating, with the loss of most of the population to introduced diseases, helped along by conquest and enslavement. But the spread of new crops and animals in both directions also helped fuel a population boom in the Old World.
Mega-empires. In Eastern Europe and Asia, the results of West European expansion by 1600 were less dramatic. There the landscape was dominated by huge empires: Russia, the Ottomans, Safavid Persia, Mughal India, Ming China. These have sometimes been called “gunpowder empires,” emphasizing the role of cannon in establishing centralized power. But they could also be considered the aftermath of the Mongol conquests, either arising from the overthrow of Mongol rule (Russia, China) or claiming direct Mongol descent (Mughal India). In other words, these empires developed in centrifugal fashion, with power collapsing at the old Mongol center, and new states arising along the Mongol marches.
Charlemagne + 800. Another centrifugal episode of state formation took place in Western and Central Europe, on a smaller scale, over a longer period of time. As the Carolingian Empire disintegrated, new states arose along its marches, in Iberia, in France, England and Scandinavia, and in eastern Germany and neighboring, mostly Slavic territory. Meanwhile the core of the former empire, including western Germany and northern Italy, remained fragmented. By earlier Roman or Asian standards, medieval states in Europe, even when they controlled large areas, were feeble things. The state’s power to collect taxes had more or less collapsed, and Medieval monarchs were forced to concede substantial privileges to their subjects in exchange for their support. By 1600, however, military competition had produced more powerful absolutist states. Medieval liberties survived best in lands where military threats had been less intense, on islands (England and Scotland), on an isolated peninsula (Scandinavia), in the mountains (Switzerland) or soggy lowlands (Holland), or just far from the madding crowd (Poland).
If a man were called to fix the period in the history of the world, during which the condition of the human race was most happy and prosperous, he would, without hesitation, name that which elapsed from the death of Domitian [96 CE] to the accession of Commodus [180 CE]. The vast extent of the Roman empire was governed by absolute power, under the guidance of virtue and wisdom. The armies were restrained by the firm but gentle hand of four successive emperors, whose characters and authority commanded involuntary respect.
Gibbon doesn’t include China in this assessment of the state of the world, but for that country too, under the Eastern Han dynasty, there was a period of stability and prosperity, lasting from the death of the usurper Wang Mang in 24 CE to the outbreak of the Yellow Turban peasant uprising in 184 CE. During this time, the Roman and Han empires so completely dominated their respective portions of Eurasia that they enjoyed relative peace. Toward the end of the second century CE, both empires had populations around 50-60 million; world population was perhaps 190 million. In the succeeding centuries both empires would experience major population declines and political collapse. As a result, the world’s total population may have declined as well.
Ian Morris’ attempt to quantify historical progress, set forth in his book The Measure of Civilization, tends to corroborate Gibbon. Roman diets and biological well-being may or may not have been very good, but their standard of living, measured by energy capture – the energy embodied in livestock, household goods, dwellings, public buildings, infrastructure, and so on – may have reached heights unmatched in the West for a millennium.
Of course Gibbon’s view is a retrospective one, and didn’t anticipate the vast rise in standards of living that eventually followed the industrial revolution.
(After this I’ll give dates as numbers without the “CE”.)
The battle to feed all of humanity is over. In the 1970s hundreds of millions of people will starve to death in spite of any crash programs embarked upon now. At this late date nothing can prevent a substantial increase in the world death rate.
Paul Ehrlich. The Population Bomb. 1968
Ironically, it was just around the time that Ehrlich wrote this that production of rice and wheat in India, the Philippines, and other countries was booming thanks to the Green Revolution – more productive plant varieties that could take advantage of fertilizer and pesticide inputs. It’s true, as Malthus pointed out long ago, that exponential population growth can eat up any conceivable increase in agricultural output. But the Green Revolution bought the world some breathing space until birth rates began to come down. It probably also eased some of the paranoia about food supply that played a part in two world wars, and the rural discontent that fueled earlier peasant revolutions.
Norman Borlaug, Green Revolution pioneer, awarded Nobel Peace Prize, 1970
Whoever makes two ears of corn, or two blades of grass to grow where only one grew before, deserves better of mankind … than the whole race of politicians put together.
Malthusianism does a pretty good job of capturing the facts of life for our species before the Industrial Revolution. For example, Malthus plus standard economics helps account for some of the historic differences between wheat and rice growing societies. And Darwinism suggests the reason why Malthusianism holds for living things in general: within a population, variants with a higher intrinsic rate of increase tend to replace those with a lower rate, even if the eventual outcome is overpopulation and misery for all. So the field of human behavioral ecology, based on the assumption that people try to maximize fitness, does pretty well in accounting for behavior in pre-modern societies.
But Malthusianism, and the assumption that people are fitness-maximizers, don’t work very well for modern societies. Even as life expectancies and standards of living have been increasing around the world, fertility rates have been declining, falling below replacement levels even in many less developed countries (although rates remain quite high in Sub-Saharan Africa.) The United States mostly follows the general trend, with a long decline in fertility rates over several centuries.
And then there’s the Baby Boom: Birth rates in the United States went up dramatically following the Second World War, then reached a peak in 1957, and continued high into the early 1960s. Young people were marrying early, and having more children. Women were staying out of the workforce to take care of the kids.
Here are two popular theories of why the Baby Boom happened that don’t work:
Soldiers coming home. The return of soldiers from the Second World War contributed to an early spike in the birth rate (visible in the chart above in the late 1940s). But the boom lasted too long to be mostly explained this way, and involved a big increase in the total number of babies born, not just people getting around to having babies that they’d put off having earlier.
Women squeezed out of the labor force. Increasing employment and educational opportunities for women are one of the long-term drivers of the demographic transition. So were these factors operating in reverse during the Baby Boom? The data clearly rule this out. Women’s wages actually rose rapidly during this period, and older women, with their child-rearing years mostly behind them, responded by entering the labor market in large numbers. In other words, employers were eager to hire women, but young women, at least, thought they had better things to do.
Instead, the best account we have comes from Richard Easterlin. He proposes that the Boom happened because young men encountered an exceptionally favorable labor market, resulting from the conjunction of several factors. (1) Birth rates fell to low levels during the Great Depression, naturally enough. As a result, twenty years on, employers faced a shortage of native-born young men looking for entry level jobs. (2) In the nineteenth century, periods of high demand for labor in the United States saw increases in immigration; levels of immigration tracked the business cycle. But in the mid-twentieth century, legal restrictions made it difficult to increase the supply of labor through immigration. Employers instead had to offer higher wages for entry level workers. Young men felt they were doing well enough – both absolutely and relative to the older generation – to get an early start on marrying, and to support their wives while raising bigger families.
The Baby Boom would be its own undoing however. As the earliest Boomers grew up and started to crowd the job market and the universities, “The Sixties” took off.
The Taiping rebellion in China began in 1850 and was finally put down in 1864. It was led by a former school teacher who discovered, after repeatedly failing his civil service exams, that he was the younger brother of Jesus Christ, destined to bring China over to his own brand of Christianity.
The rebellion was by far the most destructive conflict in the nineteenth century. It illustrates a general characteristic of Chinese history: Chinese wars were fewer but more destructive than European ones. China was unified for most of the past two millennia, governed by dynasties which established peace for long periods of time, among a huge population, over a vast area. But when things fell apart in China, whether from invasions (usually involving steppe nomads) or internal rebellions, vast numbers of people died. Here’s a chart comparing estimated numbers of war deaths for major wars Europe (red) and China (blue) between 1 and 1800 CE. China’s population during this period was somewhat less than twice that of Europe, so even per capita, China’s military catastrophes were more demographically catastrophic than Europe’s.
The Taiping rebellion comes too late to show up on the chart, but cost the lives of about 20 million people.
Pangaea reunited. In the century after 1492, West Europeans mastered the winds and currents of the world’s oceans. The shock to the rest of the world would be comparable in some ways to the earlier shock resulting from the spread of nomadism on the Eurasian steppes. In the Americas, the immediate results were devastating, with the loss of most of the population to introduced diseases, helped along by conquest and enslavement. But the spread of new crops and animals in both directions also helped fuel a population boom in the Old World.
Mega-empires. In Eastern Europe and Asia, the results of West European expansion by 1600 were less dramatic. There the landscape was dominated by huge empires: Russia, the Ottomans, Safavid Persia, Mughal India, Ming China. These have sometimes been called “gunpowder empires,” emphasizing the role of cannon in establishing centralized power. But they could also be considered the aftermath of the Mongol conquests, either arising from the overthrow of Mongol rule (Russia, China) or claiming direct Mongol descent (Mughal India). In other words, these empires developed in centrifugal fashion, with power collapsing at the old Mongol center, and new states arising along the Mongol marches.
Charlemagne + 800. Another centrifugal episode of state formation took place in Western and Central Europe, on a smaller scale, over a longer period of time. As the Carolingian Empire disintegrated, new states arose along its marches, in Iberia, in France, England and Scandinavia, and in eastern Germany and neighboring, mostly Slavic territory. Meanwhile the core of the former empire, including western Germany and northern Italy, remained fragmented. By earlier Roman or Asian standards, medieval states in Europe, even when they controlled large areas, were feeble things. The state’s power to collect taxes had more or less collapsed, and Medieval monarchs were forced to concede substantial privileges to their subjects in exchange for their support. By 1600, however, military competition had produced more powerful absolutist states. Medieval liberties survived best in lands where military threats had been less intense, on islands (England and Scotland), on an isolated peninsula (Scandinavia), in the mountains (Switzerland) or soggy lowlands (Holland), or just far from the madding crowd (Poland).
Logarithmic History 