Conference Agenda

Irrigation accounts for the largest share of global freshwater withdrawals, yet empirical evidence on the responsiveness of irrigation water demand to price signals remains fragmented, heterogeneous and often difficult to interpret for policy design. This paper conducts a comprehensive global meta-analysis of irrigation water price elasticities, synthesising nearly 400 elasticity estimates drawn from around 70 primary studies covering a wide range of crops, irrigation technologies, water sources, pricing regimes and environmental contexts. The analysis applies meta-regression techniques to explain cross-study heterogeneity through structural, institutional, technological and environmental moderators, interpreted within a Water–Energy–Food–Ecosystems (WEFE) framework.

To ensure robust inference, the study adopts an influence-based trimming strategy grounded in regression diagnostics rather than ad hoc exclusion rules. Outliers are identified conditionally, based on their leverage and influence in the regression space, and results are reported for three datasets: a full sample, a trimmed sample excluding highly influential observations and a restricted sample including only elasticity estimates based on observed water prices. This tiered approach allows explicit comparison between behavioural responses to realised pricing regimes and elasticity estimates derived from shadow or simulated prices.

Results confirm that irrigation water demand is generally price inelastic on average, but that responsiveness varies systematically across settings. Elasticities associated with groundwater use, energy-mediated pricing and multi-crop systems are significantly larger, while estimates from single-crop studies and highly water-stressed basins are markedly more inelastic. Water stress emerges as one of the most robust moderators, indicating that binding hydrological and ecosystem constraints substantially limit price responsiveness. Elasticity estimates based on observed prices display lower dispersion and higher explanatory power than those derived from constructed prices, highlighting the importance of distinguishing scarcity valuation from behavioural response.

Overall, the findings suggest that irrigation water pricing can contribute to demand management, but only under specific conditions where water–energy linkages are strong, food production systems allow adjustment and ecosystem constraints are not yet binding. From a WEFE perspective, the results caution against treating water pricing as a standalone policy instrument and underscore the need for integrated approaches that jointly address water allocation, energy pricing, cropping systems and ecosystem sustainability.