The objective of the Construction statistics operation (ECA) is to obtain information for the calculation of the main sector macro-figures, and serves as an essential basis for the production of the Input - Output Tables and the Economic accounts of the Basque Country. It is also used as the basis for other operations that produce conjunctural indicators for short economical cycles. The units of information are companies whose main activity, measured in terms of value added generated, is construction. It offers information by province by means of a territorial adjustment of the activity.