Archive for the ‘Historical’ Category

Milan, 1913

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Once a road, always a road. That’s the gist of a recent paper that studied 14 different municipalities in the Groane region of Italy near Milan. In cataloging 174 years of road construction, the study’s authors discovered that nearly 90 percent of the regions 100 most vital routes today were already present in 1833.

The researchers also uncovered evidence that the layout and characteristics of road networks are indicative of the age in which they were built. This is nothing new. Take a look at any metro region surrounded by a postwar subdivision—stick straight roads of the late 19th and early 20th centuries give way to ever more writhing tangles of spaghetti. What’s new is that this study claims that top-down planning didn’t drive the changes. Rather, the researchers say Groane’s roads reflect broader societal changes, that the unique circumstances of each era—agricultural through modern—shape road networks more than central planning—or lack thereof.

To arrive at that conclusion, physicist Marc Barthélemy and his colleagues digitized roads using maps and aerial photographs from seven different dates between 1833 to 2007. They threw the resultant vectors into a geographic information system, or GIS, and then distilled primal graphs—simplified maps that show only roads (called “links” in graph theory) and intersections (“nodes”).

Between 1833 and 2007, the number of intersections grew proportionately with population. The number of intersections skyrocketed—there were only 255 in 1833 but over 5,000 in 2007—but the number of connections remained relatively constant at 2.7 on average. The number of roads also increased linearly with the number of intersections. It’s almost as if the expansion of Groane’s social network was mirrored in its transportation corridors.

How those roads interacted with each other changed through time. In the early days, many roads either intersected another mid-link—forming a T-junction—while the others simply petered out in a dead end. Main drags radiated out from town centers like spokes on a wheel. Congruent 4-cornered intersections were rare. Yet as time progressed and cities spread into the countryside, the previous radial expansion gave way to the grid. In other studies, the advent of the grid was attributed to the arrival of master planning, but here in Groane, Barthélemy and his colleagues note that urban planning was never the region’s strong suit. Groane, they write, “never witnessed any large scale planning whatsoever.”

It is because of Groane’s lack of central planning that Barthélemy and his colleagues are able to draw their conclusion, that road networks morphed not because of changes in our approach to planning but because of changes in society as a whole. In essence, they assert that changes to the network were not consciously done.

It’s not surprising, really. Roads are built to handle the traffic of their time. When navigating Cambridge’s labyrinthine streets, I’m constantly reminded that they were built for horse and carriage, not a horseless carriage. The demands of the automobile are sufficiently different from horse or foot traffic. Their greater speeds require straighter rights-of-way. Intersections need to be clear and predictable. Navigation also needs to be simplified—drivers moving at 10 miles per hour have more time to look for their next turn than those moving three times faster. The grid tackles these problems with aplomb.

Road networks are a product of the processes that created them, whether that be wagon traffic from farm fields plodding to town or taxi cabs streaming out from downtown. Discerning process from pattern is also the domain of another field—landscape ecology. Landscape ecologists sweat the details of spatial configuration to learn what ecological processes are at work. The laws of landscape ecology apply just as well in the city as they do in the natural world. The city is nothing but an anthropogenic ecosystem.

Ever since Geoffrey West and his colleagues uncovered the mathematics behind why big cities are economically successfully—but also crime ridden—it has been popular to search for formulae that describe urban processes and city development. This paper by Barthélemy and his colleagues is but the latest addition to a growing literature. By themselves, these discoveries are clever and insightful. But the interesting stuff will happen when urban planning completes the transition from an observation-based science to a mathematical one, much as ecology did in the recent past. Then we’ll have a real sense of how these models will change our understanding of cities.

Map scanned by University of Texas PCL Map Collection.


Strano, E., Nicosia, V., Latora, V., Porta, S., & Barthélemy, M. (2012). Elementary processes governing the evolution of road networks Scientific Reports, 2 DOI: 10.1038/srep00296

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New York City skyline

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Q: Why is New York City the most populous city in the United States?

A. Because it was America’s most populous city in 1900.

Q. Why was New York City America’s most populous city in 1900?

A. Because it was America’s most populous city in 1800.

History seems to be protecting New York City’s status as the most populous city in the United States. Indeed, Paul Krugman has suggested that accidents of history gave New York City a leg up on others, and that once favored it grew into the metropolis we know today. But New York is not alone. Since 1840, the densest American cities have not only grown substantially, they also represent a larger share of the American population. The same can be said of other world cities, too. They are like snowballs—they’re big and they keep on getting bigger.

But how big cities gained the upper hand is not necessarily an accident, as Krugman’s use of the word might suggest. What has helped them grow so large is actually a specific set of geographic characteristics—location near an ocean or river (or better, both), mild climate, and ready access to natural resources. City founders may not have been working off a checklist, but they knew where to site their settlements to make the most of their surroundings.

It’s no surprise that prosperous cities are often located near large bodies of water. Water is the cheapest way to move goods, and was even more so before the Industrial Revolution. Access to navigable water meant food and raw materials could be easily brought to market and goods manufactured in the city could be cheaply exported. Water facilitated the movement of ideas, too. Both New York City and San Francisco, for example, benefitted from their status as major gateways for immigration. Immigrants were not merely a source of labor—they brought with them a diversity of ideas. Eventually, the importance of water subsided as railroads and interstate highways were built. Yet cities that were founded on coastlines or rivers continued to dominate.

Their size was the secret to their success. One of Krugman’s important early contributions was a model that showed how an already large city could grow to dominate the region. His theory was really nothing new—Johann Heinrich von Thünen described nearly the same thing in 1826—but Krugman translated the concept into today’s mathematical vernacular. Other researchers quickly picked up the thread and dug out real-world evidence of the snowball effect, including one study that looked at population growth in nearly 800 American counties between 1840–1990. It found that not only did the biggest cities grow during that time, they grew at a faster rate than other cities. New York grew more than the rest because it was bigger than the rest.

Today, New York’s fate doesn’t depend on the ocean or the river, but it does owe its status to their confluence. Its geographic past continues to steer its future. I’m tempted to haul out a favorite phrase of mine—ghosts of geography—but these cities aren’t really ghosts. They’re are very much alive. Oceans and rivers may not be as relevant to today’s world cities as they once were, but without them, many cities wouldn’t be as successful. From that perspective, it seems less likely that the founders of New York, London, and Tokyo stumbled on a happy accident and more likely that they had a keen understanding of geography.


Ayuda, M., Collantes, F., & Pinilla, V. (2009). From locational fundamentals to increasing returns: the spatial concentration of population in Spain, 1787–2000 Journal of Geographical Systems, 12 (1), 25-50 DOI: 10.1007/s10109-009-0092-x

Beeson, P. (2001). Population growth in U.S. counties, 1840–1990 Regional Science and Urban Economics, 31 (6), 669-699 DOI: 10.1016/S0166-0462(01)00065-5

Gibson, Campbell. 1998. Population of the 100 largest cities and other urban places in the United States: 1790 to 1990. U.S. Bureau of the Census, Population Division Working Paper No. 27.

Krugman, P. (1991). Increasing Returns and Economic Geography Journal of Political Economy, 99 (3) DOI: 10.1086/261763

Photo by Greg Knapp.

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La Florida, by Abraham Ortelius

In the last few years, I’ve had the good fortune of befriending a pair of Italians. Before meeting them, I admit I knew relatively little about Italian culture apart from the typical American stereotypes. I grew up in an area with strong German roots, and the college I attended maintains close ties with Norway. Needless to say, I was not well acquainted with southern European cultures.

But thanks to my friends, that’s been changing. Among other things, I’ve been picking up bits of Italian, both the standard tongue and the Veneto dialect. Italy, I’ve learned, is a country defined by a common language which many Italians don’t speak at home. There doesn’t seem to be much agreement on the exact number of dialects, but estimates range from around a dozen to over 50.

That Italy has so many dialects shouldn’t surprise an astute student of history. The region was heavily balkanized prior to unification in the mid-1800s. But Italy’s dialectal diversity may also be the product of another quirk of geography. A study done in the mid-1990s by two British professors—an evolutionary anthropologist and an evolutionary biologist—revealed a distinct trend in the languages of North American native peoples at the time of European contact. More languages were spoken in southern latitudes and the range over which those languages were spoken was smaller. In other words, language density increased closer to the equator.

The scientists discovered this trend when analyzing the first comprehensive map of the world’s languages, Atlas of the World’s Languages, which was initially published in 1993.¹ Focusing on languages spoken by native peoples when Europeans first arrived, they counted the number of tongues that a line of latitude crossed as it ran east-west across the continent. Their survey spanned 8 ˚N and ended at 70 ˚N, the furthest north an entire latitudinal span was inhabited by humans.

Upon tallying their results, a few things stood out. First, the number of languages peaked at 40 ˚N—the parallel that runs approximately through Philadelphia, Denver, and Reno.² Perhaps coincidentally—or perhaps not—this northing is also where the number of mammal species peaks in North America.³ They also discovered the number of languages per square kilometer rises exponentially as you head south. Further, the number of parallels each language intersected increased as they moved north, a function of both language density and the non-overlapping nature of native peoples’ languages at the time. Finally, the number of languages increased with habitat diversity.

The authors speculate that greater habitat diversity at southern latitudes was responsible in part for the greater density of languages. More habitat diversity tends to increase resource abundance, which would allow smaller groups of people to survive in those areas. After groups divided or a new group formed, cultural or geographic barriers may have fostered linguistic diversification.

With the advent of global communications networks, many languages and dialects are slowly dying out. That’s partially driven by the the need to communicate with ever more people in ever more places. But what’s pushing in that direction? One answer could be the world’s population. Earth is a planet of finite resources, and perhaps efficient use requires more interaction. People learned long ago that we need to cooperate to survive. Language is an amazingly efficient vehicle for that. Today, the need to cooperate—and communicate—is greater than ever.

¹ I’d love to get my hands on it, but it sells for over $700. Time to hit the library.

² The top of Italy’s boot heal is at about 40 ˚N. That’s not to imply any correlation, just to provide a frame of reference.

³ Expect more on the species-latitude relationship in a later post.


Mace, R., & Pagel, M. (1995). A Latitudinal Gradient in the Density of Human Languages in North America Proceedings of the Royal Society B: Biological Sciences, 261 (1360), 117-121 DOI: 10.1098/rspb.1995.0125

Map scanned by Norman B. Leventhal Map Center at the BPL.

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Agrippina the Younger

Over the last 30 years, wealth in the United States has been steadily concentrating in the upper economic echelons. Whereas the top 1 percent used to control a little over 30 percent of the wealth, they now control 40 percent. It’s a trend that was for decades brushed under the rug but is now on the tops of minds and at the tips of tongues.

Since too much inequality can foment revolt and instability, the CIA regularly updates statistics on income distribution for countries around the world, including the U.S. Between 1997 and 2007, inequality in the U.S. grew by almost 10 percent, making it more unequal than Russia, infamous for its powerful oligarchs. The U.S. is not faring well historically, either. Even the Roman Empire, a society built on conquest and slave labor, had a more equitable income distribution.

To determine the size of the Roman economy and the distribution of income, historians Walter Schiedel and Steven Friesen pored over papyri ledgers, previous scholarly estimates, imperial edicts, and Biblical passages. Their target was the state of the economy when the empire was at its population zenith, around 150 C.E. Schiedel and Friesen estimate that the top 1 percent of Roman society controlled 16 percent of the wealth, less than half of what America’s top 1 percent control.

To arrive at that number, they broke down Roman society into its established and implicit classes. Deriving income for the majority of plebeians required estimating the amount of wheat they might have consumed. From there, they could backtrack to daily wages based on wheat costs (most plebs did not have much, if any, discretionary income). Next they estimated the incomes of the “respectable” and “middling” sectors by multiplying the wages of the bottom class by a coefficient derived from a review of the literature. The few “respectable” and “middling” Romans enjoyed comfortable, but not lavish, lifestyles.

Above the plebs were perched the elite Roman orders. These well-defined classes played important roles in politics and commerce. The ruling patricians sat at the top, though their numbers were likely too few to consider. Below them were the senators. Their numbers are well known—there were 600 in 150 C.E.—but estimating their wealth was difficult. Like most politicians today, they were wealthy—to become a senator, a man had to be worth at least 1 million sesterces (a Roman coin, abbreviated HS). In reality, most possessed even greater fortunes. Schiedel and Friesen estimate the average senator was worth over HS5 million and drew annual incomes of more than HS300,000.

After the senators came the equestrians. Originally the Roman army’s cavalry, they evolved into a commercial class after senators were banned from business deals in 218 B.C. An equestrian’s holdings were worth on average about HS600,000, and he earned an average of HS40,000 per year. The decuriones, or city councilmen, occupied the step below the equestrians. They earning about HS9,000 per year and held assets of around HS150,000. Other miscellaneous wealthy people drew incomes and held fortunes of about the same amount as the decuriones.

In total, Schiedel and Friesen figure the elite orders and other wealthy made up about 1.5 percent of the 70 million inhabitants the empire claimed at its peak. Together, they controlled around 20 percent of the wealth.

These numbers paint a picture of two Romes, one of respectable, if not fabulous, wealth and the other of meager wages, enough to survive day-to-day but not enough to prosper. The wealthy were also largely concentrated in the cities. It’s not unlike the U.S. today. Indeed, based on a widely used measure of income inequality, the Gini coefficient, imperial Rome was slightly more equal than the U.S.

The CIA, World Bank, and other institutions track the Gini coefficients of modern nations. It’s a unitless number, which can make it somewhat tricky to understand. I find visualizing it helps. Take a look at the following graph.

Gini coefficient of inequality

To calculate the Gini coefficient, you divide the orange area (A) by the sum of the orange and blue areas (A + B). The more unequal the income distribution, the larger the orange area. The Gini coefficient scales from 0 to 1, where 0 means each portion of the population gathers an equal amount of income and 1 means a single person collects everything. Schiedel and Friesen calculated a Gini coefficient of 0.42–0.44 for Rome. By comparison, the Gini coefficient in the U.S. in 2007 was 0.45.

Schiedel and Friesen aren’t passing judgement on the ancient Romans, nor are they on modern day Americans. Theirs is an academic study, one used to further scholarship on one of the great ancient civilizations. But buried at the end, they make a point that’s difficult to parse, yet provocative. They point out that the majority of extant Roman ruins resulted from the economic activities of the top 10 percent. “Yet the disproportionate visibility of this ‘fortunate decile’ must not let us forget the vast but—to us—inconspicuous majority that failed even to begin to share in the moderate amount of economic growth associated with large-scale formation in the ancient Mediterranean and its hinterlands.”

In other words, what we see as the glory of Rome is really just the rubble of the rich, built on the backs of poor farmers and laborers, traces of whom have all but vanished. It’s as though Rome’s 99 percent never existed. Which makes me wonder, what will future civilizations think of us?


Scheidel, W., & Friesen, S. (2010). The Size of the Economy and the Distribution of Income in the Roman Empire Journal of Roman Studies, 99 DOI: 10.3815/007543509789745223

Photo by Biker Jun.

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Roman mosaic

If you want a glimpse of our ecological future, take a look at present-day Europe. Continuous and intensive human habitation for millennia have crafted ecosystems that not only thrive on human disturbance, they’re dependent on it. But even in places where pastoral uses have fallen by the wayside, the ghosts of past practices linger. If you have any doubt that the changes we’re making to the earth right now will be felt thousands of years from now, these two studies should wipe those away.

This post was chosen as an Editor's Selection for ResearchBlogging.orgThe first takes place in a post-apocalyptic landscape masquerading as a charming woods, the Tronçais forest. Smack in the middle of France, Tronçais is the site of a recent discovery of 106 Roman settlements. Photographs of the settlements call to mind Mayan ruins in Yucatan jungles, with trees overtaking helpless stone walls. Tronçais was not unique in this way—following the fall of the Roman Empire, many settlements reverted to forest after the 3rd and 4th centuries CE.

Ecologists studying plant diversity in the area noticed two distinct trends. First, the soil became markedly different as they sampled further from the center of the settlements. Nearly every measure of soil nutrients declined—nitrogen, phosphorous, and charcoal were all lower at further distances. Soil acidity declined, too. Second, plant diversity dropped off as sample sites moved further into the Roman hinterland, and likely a result of changes in the soil.

The researchers suspect the direct impacts of the settlement and Roman farming practices are behind the trends. High phosphorous and nitrogen levels were probably due to manuring. The abundance of charcoal is clearly from cooking fires, while soil pH was affected by two uses of lime common in the Roman empire—mortar used in building and marling, the spreading of lime and clay as a fertilizer. The combined effects of these practices fostered plant diversity after the settlements fell into ruin, the effects of which can be seen to this day.

The second study was undertaken by another group of ecologists who canvased grasslands in northern and western Estonia. While threatened today by the usual suspects—intensive agriculture and urbanization—the calcareous grasslands of Estonia have a long history of human stewardship which helped a wide variety of grasses and herbs to flourish. They were greatly expanded by the Vikings, who settled the area between 800 and 1100 CE. Knowing this history, the researchers suspected population density may have boosted floral diversity. They sampled exhaustively, recording plant species and communities in 15 quadrats at 45 sites for a total of 675 sample plots. They also drew 20 soil samples at each site. To estimate population density during the Viking Period, they used an established model that estimated settlement size and extent based on known ruins.

Soil qualities naturally had an affect on present-day plant diversity, but human population density during and shortly after the Viking Period also emerged as a significant predictor. As with the Roman study, changes to soil nutrients because of human activities are likely behind the results. But that’s not all. The researchers point out that seed dispersal 1,000 years ago also influenced present-day diversity. When the Vikings expanded the grasslands, they connected different patches that had previously been isolated, allowing previously isolated species to germinate in new areas.

These are not the first studies to reveal a shadow of human habitation in present day ecosystems—the Amazonian rainforest is littered with evidence of agriculture before European contact, for example. But these studies show the ghosts of ecology persisting for millennia, not centuries. Not only does it bolster the notion that no landscape is pristine—an idea that has been gaining traction with the ecological community—it should underscore the persistence of any human activity.


Dambrine, E., Dupouey, J., Laüt, L., Humbert, L., Thinon, M., Beaufils, T., & Richard, H. (2007). Present forest biodiversity patterns in France related to former Roman agriculture Ecology, 88 (6), 1430-1439 DOI: 10.1890/05-1314

PÄRTEL, M., HELM, A., REITALU, T., LIIRA, J., & ZOBEL, M. (2007). Grassland diversity related to the Late Iron Age human population density Journal of Ecology, 95 (3), 574-582 DOI: 10.1111/j.1365-2745.2007.01230.x

Photo by mharrsch.

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The United States of North America: with the British Territories and those of Spain according to the Treaty, of 1784.

This post originally appeared on Scientific American’s Guest Blog.

Borders are all-important imaginary lines that affect our lives in myriad ways. They define in a very literal sense where we live, who we call neighbors, and how we are governed. But in a world defined by instantaneous communications and commutes that can just as easily involve airports as train stations, many borders are relics of a bygone era.

The borders separating the United States’ 50 states are perfectly idiosyncratic, outmoded, even arbitrary. Obvious examples of their obsolescence abound: The New York metropolitan area has grown to encompass counties in four states. Kansas City is really two different municipalities divided by the Missouri-Kansas border. Chicago’s Metra commuter rail stretches into neighboring Wisconsin, just as Washington, D.C.’s Metro trains and busses collect riders from Maryland and Virginia.

This post was chosen as an Editor's Selection for ResearchBlogging.orgOne solution would be to throw out the old map and start fresh, something we have been doing since the dawn of time. In many cases, we’ve gone about it rather violently—examples include the conquests of the Roman army, the American Revolution, the Napoleonic Wars, World War II, and countless other conflicts. European countries with imperial dreams carved up entire continents, and when the party was over, left borders of convenience that failed to reflect economic and cultural realities.

A new map of North America, 1778Still, not all attempts to reshape the map are driven by sinister motives. Barring the Civil War, efforts to redraw state boundaries within the United States have been relatively peaceful. In the early 1940s, residents of northern California and southern Oregon toyed with the idea of forming the new state of Jefferson, because they didn’t feel either state government was meeting their needs. The attack on Pearl Harbor put an end to that, though the name of the NPR station in the region pays homage to the secessionist movement. Other campaigns have been more flash than anything else. In 1992, a state senator from eastern Washington proposed splitting the state in two, highlighting the differences within the state. And this year, a group of attorneys raised the idea that Pima County should split from the rest of Arizona, such was their frustration with state politics.

Perhaps the most sweeping proposal was floated by geographer G. Etzel Pearcy. A professor at Cal State Los Angeles, he published a book in 1973 intriguingly titled A 38 State U.S.A. Using population density as his primary guide, he carved out—you guessed it—38 states. Among them were Dearborn (southeastern Wisconsin, northeastern Illinois, northern Indiana, and southwestern Michigan), San Gabriel (southern California, Las Vegas, and the westernmost parts of Arizona), and Alamo (Texas minus the panhandle). Hawaii was the only existing state spared the knife, though Pearcy couldn’t help leaving his mark and renamed it Kilauea.

No one since Pearcy has been so bold, but a recent paper by a group of geographers, sociologists, and mathematicians has again reconsidered the layout of the lower 48 states. Though they don’t go so far as to propose a replacement map, their study sought to determine which of today’s borders have real meaning. To do so, they used bill tracking data from the site Where’s George. If you’ve handled a $1 bill in the last decade, chances are one came stamped with a short note and a URL. Upon visiting the site, you’re prompted to enter the bill’s serial number and report your current ZIP code. On the surface, it seems like a curiosity. But buried within is a trove of anonymous data on human movement and interaction.

Data from the tracked dollar bills revealed a map that in most ways is drastically different. Though there are 48 states, the researchers found evidence of only about 12 distinct regions (see map below). The Midwest remained largely in tact, as does New England. But Pennsylvania was split in two by the Appalachian Mountains, while the southern half of Georgia was given over to Florida (which in turn lost part of its panhandle to a new Gulf shores region). And as far as Where’s George data is concerned, most of the western United States is indistinguishable.

Effective borders from Thiemann et al 2011

It’s a fun exercise to imagine “what if?”, but it’s unlikely that we’ll be losing any of the 50 stars on the American flag anytime soon. There’s a good chance any proposal would be outmoded at some point in the future. Most borders are too arbitrary to stand the test of time. That doesn’t mean they’re not important—they affect our economies, governments, and more—but they can be obsoleted just as easily as they were created.


Pearcy, G. Etzel. 1973. A 38 State U.S.A. Plycon Press, Fullerton, California.

Thiemann, C., Theis, F., Grady, D., Brune, R., & Brockmann, D. (2010). The Structure of Borders in a Small World PLoS ONE, 5 (11) DOI: 10.1371/journal.pone.0015422

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Class portrait, unknown English school (undated)

Without the Industrial Revolution, there would be no modern agriculture, no modern medicine, no climate change, no population boom. A rapid-fire series of inventions reshaped one economy after another, eventually affecting the lives of every person on the planet. But exactly how it all began is still the subject of intense debate among scholars. Three economists, Raouf Boucekkine, Dominique Peeters, and David de la Croix, think population density had something to do with it.

Their argument is relatively simple: The Industrial Revolution was fostered by a surge in literacy rates. Improvements in reading and writing were nurtured by the spread of schools. And the founding of schools was aided by rising population density.

Unlike violent revolutions where monarchs lost their heads, the Industrial Revolution had no specific powder-keg. Though if you had to trace it to one event, James Hargreaves’ invention of the spinning jenny would be as good as any. Hargreaves, a weaver from Lancashire, England, devised a machine that allowed spinners to produce more and better yarn. Spinners loathed the contraption, fearing that they would be replaced by machines. But the cat was out of the bag, and subsequent inventions like the steam engine and better blast furnaces used in iron production would only hasten the pace of change.

This wave of ideas that drove the Industrial Revolution didn’t fall out of the ether. Literacy in England had been steadily rising since the 16th century when between the 1720s and 1740s, it skyrocketed. In just two decades, literacy rose from 58 percent to 70 percent among men and from 26 percent to 32 percent among women. The three economists combed through historical documents searching for an explanation and discovered a startling rise in school establishments starting in 1700 and extending through 1740. In just 40 years, 988 schools were founded in Britain, nearly as many as had been established in previous centuries.

School establishments in Great Britain before 1860

The reason behind the remarkable flurry of school establishments, the economists suspected, was a rise in population density in Great Britain. To test this theory, they developed a mathematical model that simulated how demographic, technological, and productivity changes influenced school establishments. The model’s most significant variable was population density, which the authors’ claim can explain at least one-third of the rise in literacy between 1530 and 1850. No other variable came close to explaining as much.

Logistically, it makes sense. Aside from cost, one of the big hurdles preventing children from attending school was proximity. The authors’ recount statistics and anecdotes from the report of the Schools Inquiry Commission of 1868, which said boys would travel up to an hour or more each way to get to school. One 11 year old girl walked ten miles a day for her schooling.

Many people knew of the value of an education even in those days, but there were obvious limits to how far a person could travel to obtain one. Yet as population density on the island rose, headmasters could confidently establish more schools, knowing they could attract enough students to fill their classrooms. What those students learned not only prepared them for a rapidly changing economy, it also cultivated a society which valued knowledge and ideas. That did more than just help spark the Industrial Revolution—it gave Great Britain a decades-long head start.


Boucekkine, R., Croix, D., & Peeters, D. (2007). Early Literacy Achievements, Population Density, and the Transition to Modern Growth Journal of the European Economic Association, 5 (1), 183-226 DOI: 10.1162/JEEA.2007.5.1.183

Stephens, W. (1990). Literacy in England, Scotland, and Wales, 1500-1900 History of Education Quarterly, 30 (4) DOI: 10.2307/368946

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