Guns, Germs, and Steel emphasized the role that germs played in the clash of civilizations of the early modern period, say up to about 1700. I was surprised to learn from John M. Barry’s excellent book The Great Influenza that germs continued to have a disproprtionate influence on the civilizations well into the twentieth century and perhaps even today.
The great influenza of 1918 probably killed 100 million people, about five percent of the entire world’s population. An even higher percentage of young people died and most shockingly all of this occured in about 12 weeks. Death was not evenly distributed:
The Western world suffered the least, not because its medicine was so advanced but because urbanization had exposed its population to influenza viruses so immune systems were not naked to it. In the United States, roughly 0.65 percent of the total population died, with roughly double that percentage of young adults killed. Of developed countries, Italy suffered the worst, losing approximately 1 percent of its total population….
The virus simply ravaged the less developed world. In Mexico the most conservative estimate of the death toll was 2.3 percent of the entire population, and other reasonable estimates put the death toll over 4 percent. That means between 5 and 9 percent of all young adults died.
In even more remote areas the death toll was much higher. One doctor visiting Inuit in Alaska found everyone dead in 3 villages and 7 other villages with a death toll of 85%. We don’t know how many people died in India and China but the rates were certainly higher than in the more urban United States.
By the way, an enterprising researcher should be able to make use of the 1918 influenza in Mexico (and elsewhere as well) as a shock to population that likely had important reverbations throughout the economy and society for decades.
Addendum: Bill Johnson at UVA points me to, Is the 1918 Influenza Pandemic Over? (NBER), a very recent paper by Douglas Almond. From the abstract:
In the 1960-1980 Decennial U.S. Census data, cohorts in utero during the height of the Pandemic typically display reduced educational attainment, increased rates of physical disability, lower income, lower socioeconomic status, as well as accelerated adult mortality compared with other birth cohorts. In addition, persons born in states with more severe exposure to the Pandemic experienced worse outcomes than those born in states with less severe Pandemic exposures. These results demonstrate that investments aimed at improving fetal health can have substantial long-term effects on subsequent health and economic outcomes.
Now consider, if the effects in the United States are large then in Mexico, not to mention India and China (where data will be much harder to gather), the effects could have been devastating on a macro scale.