Population dynamics in historical Roman Italy: the impact of warfare

Historians of the late Roman Republic (3rd -1st c. BCE) debate intensely over the nature of demographic developments during this period. Two opposing stances with widely divergent historical implications are being defended. One camp, the ‘low counters’ holds that Roman Italy paid a heavy toll for its military and political expansion into an Empire and experienced continued population decline. The other, the ‘high counters’ by contrast hold that population grew pronouncedly. Both base their arguments on census totals and archaeological traces of habitation that leave room for widely divergent interpretations. At the same time, available evidence on a number of demographic parameters – life expectancy, marriage ages and excess mortality rates – is not integrated into this debate. In this paper, we employ a micro-simulation model, SOCSIM, to integrate both sets of evidence. By doing so, we make explicit which assumptions underlie the opposing viewpoints on population dynamics in Roman Italy. This allows us to evaluate the respective plausibility of each of these scenarios, as it will become evident how well these required assumptions match the range of historically attested demographic parameters for the Roman world. Sophisticated demographic techniques can thus provide significant advances in a fundamental historical debate.