Height Convergence and Internal Migration in Mid-Twentieth-Century Italy

Abstract

Height convergence across Italian regions during the second half of the twentieth century is a widely recognized fact. However, it has been suggested that this process was partly affected by the massive migratory flow of people from southern to northern Italy in the 1950s and 1960s, which greatly slowed the height growth rate in the receiving regions, since immigrants were on average shorter than the receiving northern population. The main aims of this study were to estimate the speed of height convergence of Italian military conscripts in the second half of the twentieth century, and to estimate the contribution of internal migration from the south to the north of Italy to height convergence. We hypothesized that migrants from southern Italy reduced height levels among northerners relative to what they would have been without considering migration. We used cohort data on Italian conscripts born in 1951 and 1980. Results indicate that internal migration may explain from 24 to 32.7 percent of height convergence, meaning that ignoring migration flows yields an overestimation of the height changes for conscripts living in the south of Italy.

Acknowledgments

We would like to thank the principal investigator of this project, Professor C. A. Corsini, for having allowed us to use the dataset created in that study. We are very grateful to the two anonymous referees for their valuable suggestions, which enabled us to greatly improve the article.

Funding

This article is part of a Research Project of National Interest entitled “Stature, Health and Migration: Italian Conscripts” (2004) funded by the Italian Ministry of University and Research.

Notes

¹As argued by A’Hearn, Peracchi, and Vecchi (2009), “the extent to which the genetic potential is achieved is determined by net nutrition during the growing years, particularly infancy and early childhood” (1). Adolescence is also a period of intense activity in the growth process, during which the change in height rises to a peak that is about one-half of its velocity during infancy.

²McEvoy and Visscher (2009) found evidence that 80 percent of height variation is due to genetic factors, while the remaining 20 percent is controlled by environmental factors such as diet and disease exposure.

³Genetic differences between the north and the south of Italy have been stressed by several authors (see, e.g., Di Gaetano et al. 2009; Lao et al. 2008; Lynn 2010). Cavalli-Sforza, Menozzi, and Piazza (1993, 278) asserted that “Northern Italians are more similar to central Europeans whereas Southern Italians are closer to other Mediterranean people, being darker and smaller.”

⁴The contributions of state-owned enterprises and private groups, as well as the assistance of generous public and semipublic financing, were particularly decisive in driving the economic growth realized in this period. Consider that in a decade, from 1954 to 1964, per capita income rose from 350,000 to 571,000 lire. The portion of agricultural workers in the labor force also fell considerably, from 44 percent of employees in this sector in 1951 to only 18 percent 20 years later (Crafts and Magnani 2011).

⁵The strong economic growth of the central and northern areas of the country slowed down emigration to other European countries. For example, during the period 1958–63, about one-third of migration flows from the south were directed abroad, while two-thirds were toward the northwest of Italy. The main destination countries were Switzerland and Germany, which received “guest workers” who stayed for short periods (Bussini 2010).

⁶For a detailed description of ISTAT data on Italian military conscripts, see Arcaleni (2006).

⁷Arcaleni (2006) asserts that the height variation depended on differences in genetic endowments that contributed to the height variability across regions of Italy. The tallest and shortest conscripts were found in the northeast, in particular in Friuli Venezia Giulia and in the island of Sardinia, respectively.

Figure 1. Patterns of conscripts’ height (cm) in Italy by macro-area (1927–80 birth cohorts). ISTAT (1949–2003); our processing.

⁸Body height was used to identify the patterns of σ and β regional convergence for Japan before World War II by Bassino (2006), and for 1855–1910 Italian birth cohorts by A’Hearn, Peracchi, and Vecchi (2009).

⁹A first-order Taylor approximation of e^βt is used in order to linearize parameter β of equation (1), with and . See Barro (1991) for a formal derivation.

¹⁰The database used in this study was not the original one collected by each research unit participating in the “Stature, Health and Migration: Italian Conscripts” project financed in 2004. We used the database that was corrected by Professor De Iasio for errors, incongruence such as duplicates, and implausible values. We thank him for his valuable work.

¹¹Many efforts were made to create a common platform for the two cohorts of conscripts in order to facilitate both temporal and geographical comparisons between the two datasets. Some issues related to information subject to change over time (between the two cohorts) were raised. One such issue is the changing structure of Italian provinces: some adjustments were indeed necessary to guarantee comparability between the two datasets, because, between 1951 and 1980, several provinces that had not previously existed were created.

¹²We had to restrict analysis to 73 comparable provinces to estimate conditional convergence, since for some provinces, socioeconomic data were not available.