Empire is the political phenomenon that occurs when a polity expands beyond its regional economic and geographic basin. Using historical inquiry to better understand the processes by which a polity expands and maintains an empire can provide insights into the organizational forces underlying historical and modern events. These processes span economics, politics, history, anthropology and geography. This paper will explore one such process; how the construction of the Roman road network subsidized the centralization of economic activity and political power, thereby facilitating the effective control of a vast empire from a central point. A combination of economic modeling and political anthropology will, hopefully, help to explain a process that animated Roman history—and that remains active in the modern world. Specifically, this paper focuses on how the process of import replacement acts as a brake on the formation of Empire, and how the Roman subsidization and design of their road network counteracted the tendency towards import replacement. By inhibiting import replacement in its provinces,
The Import Replacement Cycle
Import replacement is the process by which settlements transition from an economy oriented towards imports and exports to an economy that replaces those imports with self-sufficient production. Import replacement was a common feature of peripheral economic zones prevalent within the
Eventually . . . the most distant farmers are so far from the existing city that it becomes profitable for some manufacturing plants to move [or emerge at] the new locations part of the way from the center to the frontier. When some firms begin to do this, they immediately generate a cumulative process of city growth in the new locations.
As peripheral economies go through the import replacement process, the economic center of gravity shifts from the political center to a virtual doughnut ring of peripheral economies (see Figure 1). The economic tendency towards import replacement acts also as an economic centrifugal force, creating an economic power vacuum in the political center. As “development led by import-replacement rather than export promotion diversifies, stabilizes, and strengthens the local economy,” import replacement leads to the rise of regional power centers that compete with the original center for control of the periphery.
The economic power vacuums created a disparity between the political and economic importance of the central point. In the case of
The built environment can also influence the process of spatial self-organization, as it creates a geography in which such economic costs are not uniformly imposed. Roads and other “man-made transportation networks are a powerful component of the self-organization of economic space.” Any society that wishes to deviate from Christaller’s optimum spacing and distribution must provide a continual input of formational energy in order to maintain a non-conforming pattern—a subsidy. Empire, a vast distortion of the preferred polity size in Christaller’s natural pattern of organization, is especially dependent on mechanisms that subsidize the energy demands of its formation and maintenance.Many of the major empires that preceded
Rubicon of Empire: Subsidization of Centralization Mechanisms
The subsidization of the means of centralization, facilitating the expansion of a polity beyond the optimal bounds of economics and geography, is the litmus test of Empire. Subsidization of the means of centralization distorts the price equilibrium of certain activities to favor those that benefit centralized control. In
As transport economists Brownlee and Heller point out, “it is essential that means of transport be properly priced so as to avoid over-allocation or under-allocation of resources to transport services as a whole, to particular forms of transport, or to particular segments of any given form.” Traditional liberal-economic theory holds that market forces will most efficiently allocate scarce resources, and that any command-input to allocate these resources—for example, to build a network of roadways—is an inefficient distortion of market forces. If Roman road construction was, therefore, economically inefficient, then why would the empire persevere on such a course for centuries? The answer is that such activity—the subsidization of the means of centralization—was necessary in order to counteract the centrifugal forces of import replacement. The Roman roads were a means of subsidizing long distance trade the viability of import replacement, helping to ensure that regional economic centers (especially in the less developed provinces) could not become sufficiently powerful to challenge Rome for control.
Roman Roads: The Calcification of EmpireThe particular feature of the Roman roads that this paper explores is their Rome-centric design methodology. The design of the road network demonstrates the strong influence of the builders’ desire to ensure that communication, trade and power flowed along roads directly “to
The geography of the
While the Roman roadways fulfilled the normal functions of roads such as trade, military transport, communications, they did so in a manner that directed power flows towards
Current theories on network architecture and the inefficiencies of hierarchy suggest that the most economically efficient road system would be distributed and decentralized—very different from the roads of
In Roman Italy, the road network radiated outwards from
Roman Britain provides another, although different, example of the role of the Roman road network in maintaining the integrity of the empire. Roman road building in
 This paper proposes the term economic/geographic Basin as the concept that the uneven geographic distribution of resources, terrain, climate, economic history, etc. creates a virtual drainage basin for economic activity, where there are economic tendencies for trade and production to pool and flow in a prearranged manner. For example, rainfall along the
toward the Gulf of Mexico and not the Pacific, unless some artificial system distortion—such as using outside energy to pump the runoff across the continental divide—overcomes the attraction of the terrain basin. A Basin performs the function of an attractor in chaos-theory.
 For additional background history on ancient
 Michael Schuman, “Going Local”: 56.
 F. W. Walbank, “The Decline of the
 Paul Krugman, “How the Economy Organizes Itself in Space: A Study of the New Economic
 Michael Schuman, “Going Local”: 56.
 Colin Renfrew and Paul Bahn, “Archaeology: Theories, Methods, and Practice”: 187.
 R. A. Wilson, “Prometheus Rising”: 63.
 To include the Egyptian kingdoms (Oriented around Nile Hydrology), Assyrian empire (
Euphrates, later adding the Nile), Mauryan (Ganges,
These were the major “hydraulic” empires that preceded
given in the opening paragraph (polity exceeding economic and geographic basin), the Egyptian kingdoms
may not qualify as an “Empire”, as they only intermittently expanded beyond the
economic and geographic region. The others pass the litmus test of Empire as they spanned more than one
river basin (each an economically and geographically optimal basin). The Hittite, Elamite, Phoenician,
Persian, Athenian and other empires Empires do not conform to Wittfogel’s “Hydraulic” concept, nor are
they adequately explained by the “Connectivity” concept of
maritime trade access to metallurgy advances have been used to explain their respective formation, but
further analysis is beyond the scope of this paper.
 Karl Wittfogel, “Oriental Despotism: A Comparative Study of Total Power.”
 Neville Morley, “Metropolis and Hinterland”: 180.
in 264-241 B.C.
in 67 B.C for the Roman general Pompey to conduct a campaign against the Cilician sea raiders. See
“Piracy Timeline” at http://pirateshold.buccaneersoft.com/pirate_timeline.html
 Raymond Chevallier, “Roman Roads”: 205.
 Ray Laurence, “The Roads of Roman Italy”: 39.
 R. A. Wilson’s SNAFU principle, see
 Raymond Chevallier, “Roman Roads”: 79-80.
 Ibid: 78.