Struttura e cambiamento nelle relazioni tra le imprese metalmeccaniche nella provincia di Modena — II. Distribuzioni degli addetti e pesi per le stime dei parametri

A database had been set up merging information incorporated in different administrative data set. The purpose was to conduct a survey on the structure and changes in the relationships between enterprises operating in the metal, machinery, and transportation industries. The distributions of the number of employees for each sub-sector of those industries, obtained from the new database, were compared with those obtained from the previous administrative archives. The Kolmogorov-Smirnov test was used to ascertain the differences observed between the various distributions, taking into account the repetition of the application of the test to protect against an error of type I. The new database was used to draw a sample of enterprises, stratified by class interval of employees and by sub-industries. Afterwards, the fundamental elements of the adopted sampling procedure and the problems relative to data collection were described: companies carrying out economic activities differing from the object of interest, dead or untraceable companies, companies subjected to internal or external changes. The strategy to obtain the weights and the precision of the estimates resulting from the data actually surveyed were presented. Moreover, in order to maintain the sample size constant and to incorporate the sampling design into the weights a set of normalized weights was calculated.