The various forms of disciplinary training that historians receive can lead to different epistemologies and thus complicate attempts to advance interdisciplinary history. For example, the epistemologies of ancient and economic historians affect both their mode of research and their style of presenting results. The testing of hypotheses through the use of simple, small-sample regressions has distinct advantages, but this approach, as well as other tools, creates not only opportunities for progress in ancient history but also obstacles for interdisciplinary history.

Hobbesian theory provides a key to understanding the interaction of economics and politics in the history of many countries, revealing that the suppression of violence is the first task of any nascent state. Only after governments have assured lasting internal peace by monopolizing violence can economic growth and political stability reinforce each other.

The available evidence on wages and labor contracts supports the existence of a functioning labor market in the early Roman empire, in which workers could change jobs in response to market-driven rewards. Slaves were included in the general labor market because Roman slavery, unlike that in the United States and in Brazil, permitted frequent manumission to citizen status. Slaves' ability to improve their status provided them with incentives to cooperate with their owners and act like free laborers. As a result, the supply and demand for labor were roughly equilibrated by wages and other payments to most workers, both slave and free.