Perdas de água e eficiência de custos no setor de saneamento básico do Brasil

Abstract

The objective of this thesis is to evaluate how water losses per connection affect the cost efficiency of water supply and sanitation service providers in Brazil and in the state of Bahia, in order to compare the results obtained at the national level with those obtained for a federation unit marked by high economic concentration in its metropolitan region. To this end, data on production, costs, and determinants of operational cost inefficiencies of these sanitation services for the period 2014 to 2021 were collected from the National Sanitation Information System (SNIS) to apply the stochastic frontier analysis methodology of costs in panel data through the Lien-Kumbhakar-Alem (LKA) model. This methodology solves the endogeneity problem arising from the inclusion of inefficiency determinants in the model and allows the joint analysis of the causal relationships between cost (in)efficiency and losses, separating the unobserved heterogeneity from the persistent and transitory cost inefficiencies of the providers. The estimates of the model based on single-product and multi-product translog cost functions showed for Brazil, at a statistical significance level of 0.1%, the rejection of the null hypothesis that water losses per connection do not affect transient inefficiency, which means that measures to combat losses may lead to an increase in the level of cost inefficiency of providers, since the savings in electricity, chemical products and other inputs in the provision of water supply services may be lower than the cost to reduce losses. Therefore, combating water losses is an environmental and cost efficiency problem. The application of the same technique to the analysis of water distribution for the state of Bahia at the municipal level, which has a high economic concentration in the metropolitan region of Salvador (RMS), showed the non rejection of the hypothesis that water losses per connection do not affect transient inefficiency. However, it was observed that the major problem of water losses in Bahia is located in the RMS, with emphasis on the municipality of Salvador, which presents exorbitant levels of losses in relation to the standard of excellence defined by the Ministry of Integration and Regional Development (MIDR), but with very high levels of efficiency in operational costs, similar to municipalities that present substantially lower losses. Therefore, caution is needed regarding the use of analysis results at the municipal level when these are operated by a single provider, since there are costs and/or expenses of the provider that for technical reasons cannot be directly allocated to the municipality, but are allocated indirectly according to some apportionment criterion; in addition, several municipalities can be served by the same water supply system. The evidence showed that there is cost inefficiency in the sanitation sector and that service providers do not have sufficient incentives to internalize in their private marginal costs the negative externalities that they generate for society. This reinforces the greater need for regulation in the sector and the adoption of measures to charge for water use that generate an opportunity cost through the generation of excess water losses so that the price of water reflects the scarcity of this economic good.