Modelling seasonality in residential water demand: the case of Tunisia
Résumé
This article proposes to model seasonal patterns of residential water
demand using the techniques of seasonal integration and cointegration.
The methodology is applied to quarterly aggregate time series data for
Tunisia (1980–2007), applying the same increasing, multi-step pricing
scheme in the whole country. First, a seasonal cointegration analysis
demonstrates the relevance of a pricing policy that increases the size of
the lower consumption block in summer. Second, the nonseasonal cointegration
analysis reveals a relatively high price elasticity for the highest
consumption block. Therefore, we also propose to increase the tariff
progressivity to promote water savings. This modified pricing scheme
will help to achieve goals of environmental protection and social equity.