As Americans receive coronavirus vaccines and the U.S. economy comes back to life, some wonder what the pandemic’s long-run consequences will be. Pandemics have influenced the course of history, felling empires, influencing colonization, and giving some groups immunological advantages.

Devastating pandemics have the potential to profoundly change how political power is distributed in society. In a recently published article, we examine how the last millennium’s deadliest pandemic — the Black Death (1347—1351) — shaped politics in Central Europe for centuries.

The Black Death affected various regions of German-speaking Central Europe very differently: In some areas, the plague killed most of the population, while other areas had a much smaller death toll. In hard-hit regions, we find that the Black Death’s impact reshaped local social and political institutions so profoundly that, even five centuries later, citizens in these regions were still voting differently.

The deadliest pandemic in human history

The Black Death was an outbreak of plague, an infectious disease caused by the bacterium Yersinia pestis. Humans mostly got it from infected rat fleas, but it could also be passed from one human to another through coughing. In the mid-14th century, Europeans had no idea what caused plague. Even if they had known, antibiotics were still centuries in the future, so they had no effective treatment. As a result, when it first spread across Europe between 1347 and 1351, the Black Death killed between 30 percent and 60 percent of the continent’s population.

The Black Death’s economic, social and political consequences

When a large proportion of the population died in a region hit hard by the Black Death, often there were not enough workers left to bring in crops. Because laborers were needed everywhere, peasants who survived could ask for higher pay and better conditions. Members of the nobility tried to lure workers from nearby manors, leading to a competitive free labor market — which sapped the power of medieval Europe’s social hierarchies. That helped end serfdom, the coercive feudal system in which peasants were obligated to work on behalf of local lords and bound to a specific manor.

Laborers became free to move as they wished. Many moved to new and growing cities. Between 1350 and 1502, for example, the population of the trade city of Lübeck grew by 35 percent. Higher wages, better living standards, freedom of movement and urbanization combined to create fertile conditions for new technologies and manufacturing. Farm land became abundant, enabling many peasants to own fields. Society became more complex and more equal.

Many new social groups emerged. These craftsmen, newly independent farmers, manufacturers, and merchants were not represented by traditional feudal political structures, and demanded a political voice. Many towns responded with electoral processes through which citizens helped decide on the mayor and town council. In other areas, newly independent farmers created institutions that allowed them to organize. All this created durable local political cultures of self-government that persisted over generations.

New political cultures shaped the rise of party politics centuries after the Black Death

As mass politics got underway in 19th-century Germany, the continuing influence of these political cultures shaped by the Black Death remained visible in citizens’ voting patterns.

In this new era of electoral politics, some elite-centered political parties crafted an antidemocratic political platform that defended the aristocracy’s power and privileges. In areas that had been subject to high plague death tolls and created democratic political cultures, this message fell flat. Citizens had gotten used to being involved in local political decisions and would not be forced to vote as elites wanted. These areas were more likely to gravitate toward liberal parties that favored all citizens’ equal rights.

For example, the duchy of Württemberg in southwest Germany had been especially hard hit by the Black Death. Its peasant villages had developed communal self-government institutions, including electing mayors. They collectively organized their farming activities, growing increasingly independent from local lords. Not surprisingly, Imperial Germany’s elitist Conservative Party fared poorly in this region with strong democratic traditions.

Half-a-century later, in the elections of the early 1930s, the Nazi party promoted illiberal views fundamentally at odds with democratic norms. Once again, citizens from areas that had developed local self-government tended to reject antidemocratic messages, voting for parties more strongly committed to democracy.

Paradoxically, then, citizens in areas less ravaged by the plague were much more likely to vote for antidemocratic and illiberal parties. There, feudal elites had continued coercive labor relationships for centuries. Residents never developed meaningful local self-government or collective decision-making. As a result, their hierarchical political cultures were fertile ground for elite-dominated political parties and the Nazis’ antidemocratic politics.

What can we learn about the political consequences of pandemics more generally?

First, not all pandemics are created equal. The Black Death’s devastating slaughter wreaked havoc on medieval labor markets, leading to profound social and political changes. Only pandemics with an immense death toll among the working-age population — which reshapes the balance of power between labor and capital — will have similarly extensive consequences.

Second, and perhaps counterintuitively, enormous loss of life can accelerate economic and political progress. It is hard to imagine the collective anguish caused by half a continent’s population dying in just a few years. Yet those who survived where the death toll was highest gained the most economic and political freedoms. In this way, pandemics can catalyze unexpected institutional innovation.

Third, the covid-19 pandemic is very different from the Black Death, with a much lower death toll. Humankind today has far more effective responses. Yet, like the Black Death, covid-19 has already spurred technological change and will likely influence politics. Countries and regions with devastating outbreaks, like India and South America, may see considerable changes in the distribution of political power.

Daniel W. Gingerich is associate professor of politics, director of the Quantitative Collaborative, and co-director of the Corruption Laboratory for Ethics, Accountability and the Rule of Law (CLEAR Lab — Democracy Initiative) at the University of Virginia.

Jan P. Vogler (@Jan_Vogler) is a postdoctoral research associate in the political economy of good government in the CLEAR Lab (Democracy Initiative) and in the department of politics at the University of Virginia. This fall, he will join the University of Konstanz in Germany as an assistant professor in quantitative social science.