Eustat

Methodological Note: Domestic trade index (ICI)

ICI. Methodological Note

DOMESTIC TRADE INDEX (ICI) OF THE AUTONOMOUS COMMUNITY OF THE BASQUE COUNTRY. BASE 2005.

The Domestic Trade Index (ICI) of the Autonomous Community of the Basque Country (CAE) is a business cycle indicator that aims to measure the evolution of sales and the number of people employed in the domestic trade sector, together with its relevant sub-sectors within the A.C. of the Basque Country.

It involves a sample survey of the commercial establishments, located in the CAE, whose main activity is wholesale trade (Class 46) according to NACE-2009 (National Classification of Economic Activities) or retail trade (Class 47).

The sample is not established by a random process, but rather by selecting companies based on Sector C of the Sectorial Trade Classification used by Eustat, which come under the various NACEs of the trade sector (Classes 46 and 47). Once selected, it is then checked that said companies are present in the three provinces of the CAE: The selection criteria, for each of the cited levels (NACE and Province), consists of guaranteeing a certain cover in each of the levels of sector C with the ideal being that it is over 75%.

The sample panel of the ICI is not closed as it could vary over time, in response to any company that is removed from the list for various reasons, and thus allowing new additions. It currently consists of 988 commercial companies.

The ICI is a weighted Laspeyres index that is based on calculated fixed weights with data from the base year. These indices have the advantage of being easy to calculate and interpret. In the first quarter of 2008, work was completed that enabled the base of the Domestic Trade Index from 2000 to 2005 to be renewed. This process included a change of the weighting coefficients used, which are obtained from the data of the Trade Accounts for 2005 and prepared by Eustat.

The linked series performed has enabled analysts and users to monitor quarterly, without breaks, the data since 1993.

In addition to its gross series, corrected and discounting the seasonal effect, the sales indices are calculated using the TRAMO-SEATS program, both in current and constant prices. The seasonal effect is also discounted from the personnel employed index. All the indices are published by province and sector, using Sectors B and C of the aforementioned Eustat Trade Classification.