The source we used in this work for the benchmark years from 1913 to 1983 is Notizie statistiche sulle principali società italiane per azioni, edited by the Associazione fra le Società Italiane per Azioni (Assonime). The Imita.db database is an electronic version of this source. This dataset contains information on companies, boards of directors, and balance sheets of a large sample of Italian joint-stock companies for several benchmark years. On the whole, the dataset contains data on more than 38,000 companies, almost 300,000 directors, and more than 100,000 balance sheets. Representativeness, in terms of capital, is very high as the sample covers well over 90 percent of the total universe in all but the first two benchmark years (1911 and 1913) and the last one (1983), for which the proportion is around 85 percent.
For the benchmark year 2001 we selected the top 250 companies from Le principali società italiane, the annual report on Italian joint-stock companies edited by R&S-Mediobanca. As this source does not report the names of the board members, we extracted them from Infocamere, a large dataset of Unioncamere, the association of the Italian chambers of commerce.
This paper focuses on seven benchmark years: 1913, 1927, 1936, 1960, 1972, 1983, and 2001. In compliance with the White Paper rules, for each benchmark year we have selected the top 250 companies by total assets, with the exclusion of subsidiaries. The top 250 companies have been selected according to the following repartition: 50 financials and 200 non financials.
As for the directors, we used only data for members of a board of directors in the strict sense, leaving out the members of Collegi sindacali. We have carefully standardized the names of the directors to make them as homogeneous as possible. However, we estimate that the information on boards of directors contained in Imita.db has a margin of error of about one percent, as is the case with other similar databases (Mintz and Schwartz 1985). These errors are mainly due to cases of homonymy, misprints, or shortcomings in the source.
Data on board members of the top 250 Italian joint-stock companies for the year 1991 are not available so we had to drop this benchmark.
