Improved Method to Calculate a Water Poverty Index at Local Scale

Abstract

Abstract:The Water Poverty Index ͑WPI͒ was created as an interdisciplinary indicator to assess water stress and scarcity, linking physical estimates of water availability with the socioeconomic drivers of poverty. This index has found great relevance in policy making as an effective water management tool, particularly in resources allocation and prioritization processes. Two conceptual weaknesses exist in the current index: ͑1͒ inadequate technique to combine available data and ͑2͒ poor statistical properties of the resulting composite. The purpose of this paper is to propose a suitable methodology to assess water poverty that overcomes these weaknesses. To this end, a number of combinations to create the WPI have been considered, based on indicators selection criteria, simple aggregation functions and multivariate analysis. The approach adopted has been designed for universal application at local scale. To exemplify the utilization of each alternative method, they have been piloted and implemented in the Turkana District ͑Kenya͒ as a case study. The paper concludes that the weighted multiplicative function is the most appropriate aggregation method for estimation of water poverty. It is least eclipsing and ambiguous free function, and it does not allow compensability among different variables of the index.

Measuring disparities in access to water based on the normative content of the human right

“…In order to aggregate indicators into subindices, two different approaches were considered: when indicators can compensate each other's performance, and the contrary. Additive aggregation has been used for the former and multiplicative aggregation for the later as it is suggested in different works (Garriga and Foguet 2010;Munda and Nardo 2005;Nardo et al 2005;Saisana et al 2002). Uncertainty and sensitivity analysis proposed elsewhere ) for the quality assessment of composite indicators are beyond the scope of this article.…”

The Influence of the Human Rights to Water and Sanitation Normative Content in Measuring the Level of Service

“…With regard to the aggregation process, it is noteworthy that linear aggregations allow compensability among the different dimensions (Munda and Nardo 2005;OECD-JRC 2008), which is not desirable in this study as different rights-based criteria are equally legitimate (United Nations 2002). We therefore opted to use a weighted multiplicative function, which is also a common aggregation method for constructing composite indicators (Blancas et al 2013;Giné Garriga and Pérez-Foguet 2010;Munda 2012;Zhou et al 2010) 2 . Numerically, the two indices can be formulated as:…”

“…Consultation with experts has the advantage of providing a flexible tool that is simple to use and easy to understand, but it is a relatively subjective method of weighting and is often singled out for its arbitrariness (Booysen, 2002). The main argument for equal indicator weights is based on the premise that no objective mechanism exists to assess the relative importance of the different aspects included in the index structure (Giné Garriga and Pérez-Foguet, 2010). This article contributes to this ongoing debate.…”

“…Indeed, accurately analyzing the relative importance of the indicators is a fundamental step when developing practical tools for sector performance monitoring, and this article proposes a method of integrating expert opinions in this process. Relevant research has suggested that the impact of weights in the final index values is reduced (Booysen 2002;Giné Garriga and Pérez-Foguet 2010;OECD-JRC 2008). However, the impact of different weighting systems on the final index-related outcomes (e.g., league tables, ranks, prioritization mechanism, etc.)…”

“…Taking into consideration the current state of the art of the approaches followed to analyse HRWS, three aspects emerge as critical issues when assessing levels of WASH services from a rights perspective: i) how to measure each dimension of both rights in the field (see Flores et al 2013), ii) how to assess the relative importance of each dimension when combining them, while ensuring that the methodologies are flexible enough to be contextually relevant, which is especially critical in the case of human rights as the mandate holder highlights (United Nations 2012), and iii) how to use adequate procedures to construct a composite indicator (Cho et al 2010;Flores et al 2013;Giné Garriga and Pérez-Foguet 2010;Hajkowicz 2006;OECD-JRC 2008). This manuscript aims to address these challenges.…”