In 1998 the Guggenheim Museum Bilbao asked a specialized consulting firm to draw up a macroeconomic survey model to assess the impact of the Museum activities in terms of wealth for the Basque Country. Since then the Museum has amended the results of the survey each year to bring them up to date and in 2001 new analytical elements were incorporated in it:
- Consideration of the induced effects.
- Inclusion of the direct expenditure made by several different companies and institutions that hold events in the Museum by hiring Museum spaces.
- Review of the expenditure profiles of visitors in accordance with their points of origin, including a new concept of leisure expenditure.
- The application of specific multipliers for each sector: retail, catering, transport, recreational and cultural activities and other business activities.