The Concentration of Personal Names in Late Medieval Florence

This study applies quantitative methods to explore the evolution of personal names in late medieval Florence. Using large historical datasets—including the “Libro di Montaperti” (1260), the “Catasto” (1427), and the “Tratte” (1282–1532)—I examine how the concentration of personal names changed over time. After assessing several possible indicators of diversification, I show that many are affected by finite-size effects and selection bias, which can distort historical interpretation. The homonymy rate, defined as the probability that two randomly chosen individuals share the same name, is identified as a robust and scale-independent metric. Applied across the Florentine sources mentioned above, this measure reveals a gradual but significant process of concentration beginning in the early fourteenth century and accelerating strongly around the time of the Black Death. The results provide a quantitative basis for dating and characterizing the long-term evolution of naming practices, illustrating how statistical reasoning can enrich the study of cultural and historical phenomena.

Measure (data warehouse) · Middle Ages · Period (music) · Selection (genetic algorithm) · Statistical analysis · Authorship Attribution and Profiling · Data Quality and Management · Names, Identity, and Discrimination Research