As in other western cities, the fast-paced urban, industrial, and commercial sprawl of Paris during the 19th century provided the backdrop and driving force for the publishing phenomenon of trade directories. We show how these collections of millions of nominative entries associated with addresses can be turned into a serial dataset whose massive, fine-grained, and geolocated nature opens up new possibilities for quantitative and multi-scale analyses of the dynamics at play during one of the most dramatic socio-spatial transformations of the city. We highlight the methodological conditions of such data-driven analyses and emphasize the importance of understanding source effects. The findings underscore the significance of data science in critically evaluating digital sources and adhering to best practices in the production of large historical datasets.
Gravier et al. (2026) studied this question.