The building process of a new integrated system of business micro-data 1989-2004

This work describes the process of building Micro.3, an integrated database containing firm level information for Italian enterprises. Micro.3 covers the period 1989–2004 and represents the development of a previous database, Micro.1 which covered a much narrower set of variables and spanned only from 1989 to 1997. This works explains the motives that drove the development of Micro.3 and it details the decisions taken during the process of construction to ensure the continuity of the existing variables as they are retrieved from different sources. Finally, we presents some statistical evidence that enables the reader to assess the quality of Micro.3.