Demand for sanitation in Salvador, Brazil: a hybrid choice approach.

Funds to promote access to water and sanitation in developing countries are scarce and most of the investments come from the national governments and households sources, not international resources. In many of these countries, mainly in middle income countries, households are paying direct taxes to access these services, and understanding what determines their choice and motivation is fundamental to promote access to them. It has been argued that is not enough to supply a wide range of alternatives unless the individuals can recognise their benefits and sustainability. The objective of this paper is to understand the choice of sanitation technology by residents in the city of Salvador, Brazil. We propose a unique hybrid choice model that incorporates a set of latent attitudinal variables and explains how the demographic factors within a household influence choice. The substantial difference of our hybrid choice model from descriptive frameworks is that it integrates choice and latent variables (such as attitudes and preferences) allowing us to model explicitly the cognitive process that influences sanitation adoption, draw conclusions from cognitive variables associated with individuals' socio-economic and demographic characteristics, and establishes a causal pathway among these variables. The results show that the attributes of health protection, accessibility, privacy, and house modernisation were what households cared about when opting for flush toilet and sewerage connection, rather than the high cost and consequent household socio-economic status associated with them. The hybrid model is statistically consistent with these findings, and seems to fill the gap between behavioural theory and discrete choice models applied to sanitation.