Numeracy and consistency in age declarations: a case study on nineteenth and twentieth century Catalonia

A rich tradition exists on measuring human capital in historical societies through basic mathematical skills using the method of age heaping. In this article, we novelty propose to calculate it also through the analysis of the consistency in individual consecutive age declaration statements in five towns of Baix Llobregat’s county (Barcelona, Spain) during the nineteenth and early twentieth centuries. The region underwent a proto-industrialization in the eighteenth century and was one of the main wool and cotton textile producers in the nineteenth century in Catalonia. Our main results show that (I) numeracy levels in this county were above the Spanish average in the whole period and, during the first years of the nineteenth century, ahead of countries such as Italy, Portugal and the USA. However, its numeracy dropped from 1880’s due the early industrialization of Catalonia in the Spanish and Southern Europe context, the existence of child labor in the factories and that also coincided with the phylloxera crisis. (II) To this effect, women presented lower levels of numeracy than men, but their levels tended to converge. (III) As regards emigrants, those who came to the rest of Spain had the lowest level of numeracy compared to the natives. (IV) Moreover, we found that literacy, the 1901 education reform and a higher socioeconomic status had a positive effect on reporting ages consistently over time. (V) Finally, we prove a positive association between systematically reporting ages ending in 0 or 5 and having a higher individual error in age statements along the life course.