An interesting little piece of research showing just quite how old some of the roots of economic prosperity can be. And shown using the most modern technology as well. For some years now economists have been measuring economic development by the amount of light that can be seen in satellite photographs of an area. For one of the very first things people seem to do, as soon as they can, is to light up that bulb rather than curse against the darkness. The technique has been used to estimate African GDP growth for example, coming to much more cheering results than the official figures would have us believe. And here it's used to measure quite how old some of the roots of successful development might be:
In ancient times, the area of contemporary Germany was divided into a Roman and non-Roman part. The study uses this division to test whether the formerly Roman part of Germany show a higher nightlight luminosity than the non-Roman part. This is done by using the Limes wall as geographical discontinuity in a regression discontinuity design framework. The results indicate that economic development—as measured by luminosity—is indeed significantly and robustly larger in the formerly Roman parts of Germany. The study identifies the persistence of the Roman road network until the present as an important factor causing this development advantage of the formerly Roman part of Germany both by fostering city growth and by allowing for a denser road network.
It's a very interesting little piece of work.