For certain question of economic and social interest it is necessary to regroup the relevant data. Although these are contained in the initial tables – for example, in the national accounts- the relevant question cannot be realised due to an overly high degree of aggregation or a conducted classification according to specific criteria.
For example, tourism, sport, the security sector or the health sector, from an econometric point of view, do not represent sharply defined branches of industry, but cross-sectional matters. Their activities involve a larger number of sectors in a direct manner, but they are not recorded or reported in the desired thematic classification or at the desired level of detail as such within the national accounts.
In order to make these economic activities and mutual interconnections visible, special input-output-tables for such cross-sectional matters are developed. Since these expansions of the national accounts, whose base-tables, analogous to a satellite, orbit the entire system from a 360° perspective, in order to extract the relevant information from all various accounts of the national accounts, the same are called satellite-systems.
This simplified 3-sector-model shows how the columns and rows of the original input-output-table are extended by the economic segments (S1 and S2) generated by the satellite account.