What counts as rural? Evidence from Southern Spain, 1787–2017

The demographic decline of the rural world is usually seen as solid evidence of long-run economic and social development. Its correlate, urbanization, plays a key role in studies of comparative development. And yet, this is often founded on shaky empirical grounds: what exactly counted as rural in the past(s)? We compare the many thresholds used by historians to define the rural/urban boundary and, through the case of modern southern Spain, show that even apparently small changes to the criteria result in substantial variation in both levels and trends of rural population. This leads us to suggest that sensitivity analyses should be standard in empirical work that relies on historical urbanization rates or exploits differences between rural and urban places (in fertility, productivity, etc.). We warn against the rigidities implied in the criteria to distinguish between rural and urban, and ask that historians (and historically-minded social scientists) are mindful of the actual magnitude of the gap between the estimates produced by different methods.