Estimating Water Demand Using Price Differences of Wastewater Services
Nathan DeMaagd and
Michael Roberts
No 202019, Working Papers from University of Hawaii at Manoa, Department of Economics
Abstract:
Many homes in Hawaii use cesspools and other on-site disposal systems (OSDS) instead of the municipal sewer system. Because bills combine water and waste-water services, and homes with OSDS do not pay for sewer service, OSDS residences have lower monthly bills compared to those with sewer-connected systems. We use this price difference in conjunction with selection on observables and matching methods to estimate the price elasticity of residential water demand. Matching methods indicate that OSDS residences have systematically different characteristics than those with sewer-connected systems, suggesting an imperfect natural experiment. We show traditional methods lead to biased elasticity estimates, even though they are robust when selecting on observables using OLS with or without census tract fixed effects, census block fixed effects, and non- parametric controls trained using cross-validation and a lasso. We then estimate demand using a limited sample of OSDS homes that have sewer-connected neighbors, which gives estimates from -0.06 to -0.08. The neighbors have no systematic differences in other characteristics and estimates are robust to further selection on observables, but the sample differs slightly from population means in their physical characteristics. These more defensible demand elasticity estimates, however, are much more inelastic than estimates not based on comparison of neighbors and are generally more inelastic than previous studies. Taken collectively, the results highlight the susceptibility of demand estimates to omitted variable bias. Highly inelastic water demand suggests that considerably higher prices may be needed for sustainable water management, creating some practical challenges under current regulatory guidance. We also use our results to estimate willingness to accept a tax credit for upgrading an OSDS system, a targeted policy that aims to improve water quality. Regardless of whether consumers respond to average or marginal prices, our estimates imply that the tax credit is far too small to induce voluntary participation in the program. Additional consumer welfare topics are also considered.
Keywords: water demand; elasticity; consumer welfare (search for similar items in EconPapers)
JEL-codes: Q21 Q25 (search for similar items in EconPapers)
Date: 2020-07
New Economics Papers: this item is included in nep-env and nep-reg
References: View references in EconPapers View complete reference list from CitEc
Citations:
Downloads: (external link)
http://www.economics.hawaii.edu/research/workingpapers/WP_20-19.pdf First version, 2020 (application/pdf)
Related works:
Working Paper: Estimating water demand using price differences of wastewater services (2020) 
This item may be available elsewhere in EconPapers: Search for items with the same title.
Export reference: BibTeX
RIS (EndNote, ProCite, RefMan)
HTML/Text
Persistent link: https://EconPapers.repec.org/RePEc:hai:wpaper:202019
Ordering information: This working paper can be ordered from
http://www.economics ... esearch/working.html
Access Statistics for this paper
More papers in Working Papers from University of Hawaii at Manoa, Department of Economics Contact information at EDIRC.
Bibliographic data for series maintained by Web Technician ().