Author Archives: msoderhall

Ancient Infrastructure and Economic Activity


Roman Roads to Prosperity: Persistence and Non-Persistence of Public Goods Provision

Carl-Johan Dalgaard (University of Copenhagen and CEPR), Nicolai Kaarsen (Danish Economic Council), Ola Olsson (University of Gothenburg) and Pablo Selaya (University of Copenhagen)

Abstract: How persistent is public goods provision in a comparative perspective? We explore the link between infrastructure investments made during antiquity and the presence of infrastructure today, as well as the link between early infrastructure and economic activity both in the past and in the present, across the entire area under dominion of the Roman Empire at the zenith of its geographical extension. We find a remarkable pattern of persistence showing that greater Roman road density goes along with (a) greater modern road density, (b) greater settlement formation in 500 CE, and (c) greater economic activity in 2010. Interestingly, however, the degree of persistence in road density and the link between early road density and contemporary economic development is weakened to the point of insignificance in areas where the use of wheeled vehicles was abandoned from the first millennium CE until the late modern period. Taken at face value, our results suggest that infrastructure may be one important channel through which persistence in comparative development comes about.


Distributed by NEP-HIS on: 2018-03-26

Revised by: Martin Söderhäll (Uppsala University)


In the paper Roman Roads to Prosperity: Persistence and Non-Persistence of Public Goods Provision the question “How persistent is public goods provision in a comparative perspective?” is examined by estimating the impact of Roman road-density on various proxies for economic activity today (modern roads, night-lights and population density) and in 500 CE (roman settlements). This is done for areas of Europe, the Middle East and Northern Africa covered by Roman roads in 117 CE. The authors argue that the Roman roads “almost presents itself as a natural experiment” since the main purpose of the roads was to simplify military logistics during Roman times. This led to a road network with roads constructed as straight as possible between nodes, especially in newly conquered and undeveloped areas of the Roman Empire.

roman roads_paris

Figure 1: Roman Roads and Night Lights around Paris

The main findings in the paper are that Roman road density in 117 CE has a statistically significant positive effect on all of the above-mentioned dependent variables, suggesting that the spatial distribution of ancient infrastructure still affects the location of economic activity almost 2000 years later. However, the historical density of ancient infrastructure is not enough to explain the density of modern infrastructure as well as economic activity. The authors hypothesize that persistent use and maintenance of said infrastructure is a necessary condition for the link. To examine the hypotheses the authors’ exploit regional variation in the use of wheeled transport during the first millennia CE. This historical natural experiment is made possible since the Middle East and North Africa abandoned wheeled transport during this period, most probably due to the use of camels, which became a more efficient means of transportation in the region some time during the first millennia (Bulliet 1990).


Figure 2: Roman Roads Network in 117 CE

The developments in the Middle East and North Africa during the first millennia CE led to ancient Roman roads being used to much lesser extent than in Europe were wheeled vehicles (drawn by horses or oxen) continued to dominate among land-based means of transportation up until the nineteenth century. Thus, the authors’ claim, “one should expect influence of Roman roads today only where persistence in infrastructure is found.” In other words, the effect of Roman roads on economic activity today should be insignificant within the Middle East and in North Africa while it should have a positive effect within Europe. However, one should also expect that the density of Roman roads had a positive effect on economic activity in all studied regions before the abandonment of the wheel and the subsequent loss of interest in the use and maintenance of Roman roads in the Middle East and in North Africa.


Figure 3: Relationship between Roman Road Density in 177 CE and Modern Road Density

Econometrically, the hypotheses set by the authors are examined by a cross-sectional specification where the parameter of interest is the influence of Roman road density on various measures of economic activity today and in 500 CE, controlling for (primarily) geographic traits of the grid cells where road density are measured as well as country and language fixed-effects. The empirical results are in line with those hypothesized by the authors. The density of Roman roads had a statistically significant positive effect on economic activity in all specifications except the ones where the modern day variables capturing the degree of economic activity “today” is regressed on Roman road density in the Middle East and North Africa, further strengthening the argument that persistence in infrastructure can explain comparative development over a period of 2000 years.


The interpretation and implication of the empirical result is quite straightforward. It is clearly a good idea to keep investing in infrastructure as long as the infrastructure has an economic value, something the authors show was the case in Europe but less so in the Middle East and North Africa where the value of Roman infrastructure dropped. At first sight, one potential remark is the large time gap between the cross sections. How would the interpretation of the results look like if the link between Roman roads and economic activity disappeared in large parts of Europe some time during the period 500-2010 CE? Results from previous research (Bosker et. al. 2013; Bosker & Buringj 2017) ease the worry of this question slightly, since they have shown a relationship between Roman road-hubs and city sizes during the period 800-1800. However, it would have been nice to see some specifications for the years between 500 CE and 2010 CE in this paper as well, possibly using city sizes from DeVries (2013) or Bairoch (1991) as a proxy for economic activity. Especially since the scope differs a bit from that in Bosker et. al. (2013) where the estimation (to my knowledge) is done in a panel setting and in Bosker & Buringj (2017) where only Europe is studied.

Aside from that, I have very little to remark on; I find the argumentation against potential threats to internal validity convincing, and find arguments against external validity quite irrelevant due to the exploratory nature of the paper. In a way, the paper can be summarized as both fun and fascinating.


Bairoch, P. (1991). Cities and Economic Development: From the Dawn of History to the Present. Chicago, IL: University of Chicago Press.

Bosker, M., Buringh, E., & van Zanden, J. L. (2013). “From Baghdad to London: Unraveling Urban Development in Europe, the Middle East, and North Africa, 800–1800.” Review of Economics and Statistics, 95 (4), 1418-1437.

Bosker, M., & Buringh, E. (2017). “City Seeds: Geography and the Origins of the European City System.” Journal of Urban Economics 98, 139-157.

Bulliet, R. W. (1990). The Camel and the Wheel.  New York, NY: Columbia University Press.

De Vries, J. (2013). European Urbanization, 1500-1800. London: Routledge.


Spatially-Embedded Collective Memory and Political Behaviors

Activated History – The Case of the Turkish Sieges of Vienna

Christian Ochsner and Felix Roesel (Ifo Institute – Leibniz Institute for Economic Research at the University of Munich Dresden Branch)

Abstract: We study whether long-gone but activated history can shape social attitudes and behavior even after centuries. We exploit the case of the sieges of Vienna in 1529 and 1683, when Turkish troops pillaged individual municipalities across East Austria. In 2005, Austrian right-wing populists started to campaign against Turks and Muslims and explicitly referred to the Turkish sieges. We show that right-wing voting increased in once pillaged municipalities compared to non-pillaged municipalities after the campaigns were launched, but not before. The effects are substantial: Around one out of ten votes for the far-right in a once pillaged municipality is caused by salient history. We conclude that campaigns can act as tipping points and catalyze history in a nonlinear fashion.


Circulated by NEP-HIS on: 2017-11-05

Revised by Martin Söderhäll (Uppsala University)


The Turkish Siege of Vienna (1529). Collection: Vienna Museum. Source: Wikimedia Commons.

a) Summary

Is it possible for “arguably irrelevant” historical events to shape the voting behavior of a population if triggered by political campaigning exploiting said historical events? This is the main question the authors set out to answer in the paper. The authors show that political campaigning that uses stereotypes of religious and ethnic minorities can be highly effective when encountering spatially embedded collective memory utilizing a set of seemingly unique historical and societal circumstances occurring in present day Austria, among other things: 1. The pillaging of Austrian villages by Turkish troops during the Ottoman military expeditions in the 16th and 17th centuries. 2. The presence of one of Europe’s oldest and still existing right-wing populist parties (the Freigeitliche Partei Österreich, FPÖ) which in 2005 started to campaign against Muslims and Turks explicitly referring to “their vicious crimes during the Turkish sieges of Vienna” and 3. The arguably exogenous location of the Battle of Bisamberg which led to spatial discontinuity in the probability of villages being pillaged by the Turks north of the Danube during the second siege of Vienna in 1683.


The empirical strategy is directed towards examining if the vote share of the Austrian right-wing populist party (FPÖ) was significantly higher in villages exposed to Turkish pillaging in the 16th and/or the 17th centuries (i.e. in villages were the collective memory of Turkish pillages was stronger) than in villages that were not pillaged, right after the change in campaign tactics of the FPÖ in the year 2005. Using the “tools of the trade” of 21st century economic historical research (the baseline model uses a traditional DiD approach, although the spatial fuzzy RD design using panel data, seen in section 4.3 is new according to the authors), Ochsner and Roesel find that having been exposed to pillaging in the 16th and the 17th centuries led to an activation effect (i.e. the average treatment effect) of 1.6-3.05 percent depending on the specification. The larger effect sizes, 2.5-3.05 percent are estimated using the spatial fuzzy RD design on the sub sample of villages west of Vienna.


The authors conclude that neither “a local historical record of foreign atrocities” or “a campaign that addresses the stereotypes of these foreigners” are necessary and sufficient conditions to activate any effect. However, when both conditions are met the effect is statistically significant and robust across a range of specifications. In section 7 of the paper the authors address the underlying mechanisms at work. Ochsner and Roesel find that the effects of the campaigning were stronger in small rural communities and in communities with a lower share of out-commuters. Their findings suggest that “collective memory is likely to be a function of local embeddedness”. The authors conclude their paper with a call for future research that addresses the fact that societies can evolve and interact in a non-linear manner.

b) Comments

In general, I tend to approach quasi-experimental long-run effects papers with seemingly robust and large effects on the treatment group, with a bit of skepticism. In this case however, at least from my point of view, the authors made an excellent job of convincing me of (at least) the internal validity of their study. This is in part thanks to the appealing empirical setting, which they carefully account for in the introduction, and the two following sections of the paper.  The use of pictures and references to visual remnants of history in East Austria as well as quotes of “anti-Turkish” comments in online forums and the analysis of FPÖ’s campaign content provides context to readers unfamiliar with the setting, which is great!


While I find the authors interpretation of the mechanisms at work plausible, the empirical examination of said mechanism lacks the attention to detail shown in section 4-6. Collective memory might well be a function of local embeddedness; however, the authors use the share of out-commuters from a village as a proxy for embeddedness. Arguably this variable could also be a proxy for a lot of other things such as the average income or the age structure of the population in the villages (which they do not control for in the models presented in table 13). Addressing the mechanisms at work more carefully would in my opinion further improve the paper.

As a final comment, the results provided by the authors raises many interesting questions. The possibility to activate history in places were a collective memory of past events is present by campaigning could be utilized by a range of actors. In this day and age when the costs for highly customized political advertising (on social media platforms for example) is lower than ever before, “activating history” could be utilized by political parties (or other interest groups) in locations were the probability of a positive effect is higher, whilst other (less controversial) campaigning strategies could be used in other locations. The fact that the authors implicitly raise the awareness of how distant history in subtle ways can influence our opinions is truly a good thing.