The effectiveness of pricing policies depends on the price elasticity of consumption. It
is well documented that residential demand for water is influenced by heterogeneity
associated with differences in the size of the household and socioeconomic characteristics.
In this paper, we focus on household size. Our initial hypothesis is that users’ sensitivity
to changes in price is different depending on the number of household
members. To this end, we carry out an empirical estimation of urban water demand in
Zaragoza (Spain) distinguishing between households with different sizes using data at
the individual level. As far as we are aware, this approach to urban residential water
demand is new in the literature. The analysis suggests that all households are sensitive
to prices regardless of size. A more relevant finding is that small households are more
sensitive to price changes
