of loyalty to the Roman government in favor of loyalty to commanders. Ferrill agrees with other Roman historians such as A.H.M. Jones: Michael Rostovtzeff, Ludwig von Mises, and Bruce Bartlett: excessive government Historian Michael Rostovtzeff and economist Ludwig von Mises both argued that unsound economic policies played a key role in the impoverishment and decay of the Roman Empire. According to them, in the second and third century, the Roman Empire developed a complex market economy in which trade was relatively free. Using Marxist terms, Rostovtzeff in 1926 argued that the roots of Roman decline were the "alliance of the [regressive] elements of the rural proletariat with the military destroyed the beneficient rule of an urban bourgeoisie." Mises in 1959 said the ruin of Rome was due to inflation and government intervention in the economy, especially with price controls that did not reflect market realities. Bruce Bartlett followed in the footsteps of Rostovtzeff and Mises. He titled his 1994 essay, "How Excessive Government Killed Ancient Rome." He said that "the fall of Rome was fundamentally due to economic deterioration resulting from excessive taxation, inflation, and over-regulation." Joseph Tainter: diminishing returns In his 1988 book The Collapse of Complex Societies, American anthropologist Tainter presents the view that for given technological levels there are implicit declining returns to complexity, in which systems deplete their resource base beyond levels that are ultimately sustainable. Tainter argues that societies become more complex as they try to solve problems. Social complexity can include differentiated social and economic roles, reliance on symbolic and abstract communication, and the existence of a class of information producers and analysts who are not involved in primary resource production. Such complexity requires a substantial "energy" subsidy (meaning resources, or other forms of wealth). When a society confronts a "problem", such as a shortage of or difficulty in gaining access to energy, it tends to create new layers of bureaucracy, infrastructure, or social class to address the challenge. For example, as Roman agricultural output slowly declined and population increased, per-capita energy availability dropped. The Romans solved this problem in the short term by conquering their neighbours to appropriate their energy surpluses (metals, grain, slaves, etc.). However, this solution merely exacerbated the issue over the long term; as the Empire grew, the cost of maintaining communications, garrisons, civil government, etc., increased. Eventually, this cost grew so great that any new challenges such as invasions