The ESEE's population of reference is made up by the firms with 10 or more employees and which belong to what is usually known as the manufacturing industry. The geographical scope of reference is all the Spanish territory, and the variables have a yearly temporal dimension.

One of the most relevant characteristics of the ESEE is its representativeness. The initial selection was carried out combining exhaustiveness and random sampling criteria. In the first category were included those firms which have over 200 employees, and whose participation was required. The second category was composed by the firms which employ between 10 and 200 workers, which were selected through a stratified, proportional, restricted and systematic sampling, with a random start. In the first year, 1990, 2,188 firms were interviewed along the above mentioned criteria. Later special care has been paid to maintaining its representativeness with regard to the population of reference. The effort has been oriented, on the one hand, to reducing as far as possible, the deterioration of the initial sample, trying to avoid the reduction of the firms' collaboration, and on the other, including each year into the sample all the newly incorporated firms which employ over 200 workers, as well as a randomly selected sample which represents around 5% of the newly incorporated firms which have between 10 and 200 employees.

The table "Summary of the sample's evolution in the years 1990-2007 (All the firms)" shows the evolution of the sampled firms during the period 1990-2007.

Select the appropriate option if you wish a summary of the sample for the firms which at the beginning employed:
         1.- Firms with 200 or less employees
         2.- Firms over 200 employees

To obtain information about the representative sample, you can link here .