Water Supply Services in Spanish Cities and the Debate on Private Participation in Their Management: Which Model is Most Efficient?

Abstract Supplying water to the population is one of the fundamental services of any Spanish city given the importance of the good itself, regardless of how it is managed. However, it is sometimes seen more as a source of extra finance for the municipality, and, in recent years, as an issue of political debate in terms of the adequacy of one form of management or another: public or private. Currently, 35% of Spain's population is supplied by public specialised entities, 33% by private companies under a concession contract, 22% by mixed companies and 10% by undifferentiated municipal services. In simple terms, 45% corresponds to public management and 55% is fully or partially managed by the private sector. By analysing the annual accounts of the companies that operate in the Spain's principal municipalities, this study seeks to determine the role played by the private sector in the management of the mixed companies. Due to the diversity of services provided by these companies and the lack of differentiated statistics for each of them, we have used the Annual Accounts presented to the Central Mercantile Register or the data submitted to the Ministry of Finance in order to assess the influence of private participation on the results of the companies.