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I'm not an economist or a historian but I wonder if there is an aspect to Roman wealth here that isn't captured well by GDP. As an example, Roman roads are famo

I'm not an economist or a historian but I wonder if there is an aspect to Roman wealth here that isn't captured well by GDP. As an example, Roman roads are famous for their durability, whereas modern highways (which experience very different traffic) need to be repaved on the order of years or decades. For the same distance of road, it would seem a great deal more economic activity in the form of labor, construction, and materials is needed to sustain a modern roadway. If key Roman infrastructure investments simply had a longer lifetime than modern infrastructure (because of design, requirements, etc.), wouldn't that imply the per capita wealth of the empire could be high without a particularly high GDP? Curious if there is any literature about this.

chromaton 9y ago
We only remember the stuff that actually lasted.
sliverstorm 9y ago
It sounds like you're basically arguing for the use of NDP, net domestic product. Wear on roads et cetera is the cost of the added (design, requirements, etc) of that higher GDP, and NDP would be the net benefit.
- njarboe 9y ago
  GDP is not good measure of wealth, happiness, or greatness of a country. It is useful for the government to increase it when the government taxes income and sales. If everything was made to last forever and we had already produced everything we needed, GDP could be almost zero (food production in US about 2% of GDP?) and the people could be doing great.
hjnilsson 9y ago
A very important aspect to consider here is that a roman road did not have 100 000+ multi-ton vehicles traveling on them per day. The reason roman roads lasted long is that the load on a road with only manual labor traffic is a thousand times less than that of a modern highway. Old roads in Europe that are subject to truck and car traffic crumble very quickly unless meticulously maintained.
- ramblenode 9y ago
  Perhaps I wasn't explicit enough in the post, but yes I realize this. The point I was trying to make is that whatever the reason (including the purpose of the infrastructure, its usage patterns, its requirements), if a project could satisfy its purpose with fewer resources/less GDP needing to be reinvested over time, then this represents a higher relative return on their investment. GDP, having the dimension of time, wouldn't necessarily reflect their overall wealth, including the uncounted utility from historical investments.
  - bryondowd 9y ago
    The upfront investment of a Roman road might still be comparable to the lifetime investment of a modern one when you factor the human resource. How many man hours are spent on a mile of road, including building the tools (cement truck, bulldozer, etc) now versus the mass manual labor required then.
  - deleted 9y ago
    [deleted]
- jdmichal 9y ago
  And even then, most road degradation is due to heavy trucks. Cars contribute very little. http://facweb.knowlton.ohio-state.edu/pviton/courses2/crp776/776-roads-handout.pdf http://facweb.knowlton.ohio-state.edu/pviton/courses2/crp776... Skip to page 4, where it covers ESAL. A standard trailer is expected to do around 800-1000 times the damage of a standard passenger car. The conclusion: "When discussing road wear cars don't matter: road damage is effectively caused by trucks."
  - B1FF_PSUVM 9y ago
    > road damage is effectively caused by trucks. So, if road use is charged by a steeply progressive schedule, and driver cost is not an issue, will we see fleets of light autonomous trucks replace the heavyweights?
    - 9y ago
dredmorbius 9y ago
There are several elements of Roman wealth which aren't captured by GDP (or alternatively, of the overreporting of modern wealth by GDP). One element is infrastructure depreciation. As you note, the materials and construction of Rome tended to last. Stone and Roman concrete both in particular don't degrade with time (though they may suffer earthquake damage). Things built tended to remain built over timescales we are not familiar with, at the very least, centuries rather than decades. Depreciation expense was far less. Another factor was a much smaller natural capital expense. Not an entirely absent one, and there were problems with deforestation, salinisation, and cropland depletion throughout the Roman empire, as well as hazards introduced by commerce of plague and disease. But the major capital depletion of the modern world, the draw-down of fossil-fuel reserves at rates millions of times greater than their formation, was not present, nor various consequences of such actions, including of course, greenhouse-gas induced global warming and ocean chemistry changes. (Among the issues Rome did have to deal with was heavy metal pollution, particularly lead and mercury, and particulates emissions. It wasn't all roses. But by relative magnitudes this was a very small fraction of present capital expenditures.) Vaclav Smil's Energy and Civilization is an epic exploration of the role of energy in history, including the Roman Empire. https://mitpress.mit.edu/authors/vaclav-smil https://mitpress.mit.edu/authors/vaclav-smil

chromaton 9y ago

We only remember the stuff that actually lasted.

sliverstorm 9y ago

It sounds like you're basically arguing for the use of NDP, net domestic product. Wear on roads et cetera is the cost of the added (design, requirements, etc) of that higher GDP, and NDP would be the net benefit.

njarboe 9y ago
GDP is not good measure of wealth, happiness, or greatness of a country. It is useful for the government to increase it when the government taxes income and sales. If everything was made to last forever and we had already produced everything we needed, GDP could be almost zero (food production in US about 2% of GDP?) and the people could be doing great.

hjnilsson 9y ago

A very important aspect to consider here is that a roman road did not have 100 000+ multi-ton vehicles traveling on them per day. The reason roman roads lasted long is that the load on a road with only manual labor traffic is a thousand times less than that of a modern highway. Old roads in Europe that are subject to truck and car traffic crumble very quickly unless meticulously maintained.

ramblenode 9y ago
Perhaps I wasn't explicit enough in the post, but yes I realize this. The point I was trying to make is that whatever the reason (including the purpose of the infrastructure, its usage patterns, its requirements), if a project could satisfy its purpose with fewer resources/less GDP needing to be reinvested over time, then this represents a higher relative return on their investment. GDP, having the dimension of time, wouldn't necessarily reflect their overall wealth, including the uncounted utility from historical investments.
- bryondowd 9y ago
  The upfront investment of a Roman road might still be comparable to the lifetime investment of a modern one when you factor the human resource. How many man hours are spent on a mile of road, including building the tools (cement truck, bulldozer, etc) now versus the mass manual labor required then.
- deleted 9y ago
  [deleted]
jdmichal 9y ago
And even then, most road degradation is due to heavy trucks. Cars contribute very little. http://facweb.knowlton.ohio-state.edu/pviton/courses2/crp776/776-roads-handout.pdf http://facweb.knowlton.ohio-state.edu/pviton/courses2/crp776... Skip to page 4, where it covers ESAL. A standard trailer is expected to do around 800-1000 times the damage of a standard passenger car. The conclusion: "When discussing road wear cars don't matter: road damage is effectively caused by trucks."
- B1FF_PSUVM 9y ago
  > road damage is effectively caused by trucks. So, if road use is charged by a steeply progressive schedule, and driver cost is not an issue, will we see fleets of light autonomous trucks replace the heavyweights?
  - 9y ago

dredmorbius 9y ago

There are several elements of Roman wealth which aren't captured by GDP (or alternatively, of the overreporting of modern wealth by GDP). One element is infrastructure depreciation. As you note, the materials and construction of Rome tended to last. Stone and Roman concrete both in particular don't degrade with time (though they may suffer earthquake damage). Things built tended to remain built over timescales we are not familiar with, at the very least, centuries rather than decades. Depreciation expense was far less. Another factor was a much smaller natural capital expense. Not an entirely absent one, and there were problems with deforestation, salinisation, and cropland depletion throughout the Roman empire, as well as hazards introduced by commerce of plague and disease. But the major capital depletion of the modern world, the draw-down of fossil-fuel reserves at rates millions of times greater than their formation, was not present, nor various consequences of such actions, including of course, greenhouse-gas induced global warming and ocean chemistry changes. (Among the issues Rome did have to deal with was heavy metal pollution, particularly lead and mercury, and particulates emissions. It wasn't all roses. But by relative magnitudes this was a very small fraction of present capital expenditures.) Vaclav Smil's Energy and Civilization is an epic exploration of the role of energy in history, including the Roman Empire. https://mitpress.mit.edu/authors/vaclav-smil https://mitpress.mit.edu/authors/vaclav-smil