The short version
Dozens of studies have asked whether homes near cleaner lakes and bays sell for more. Economists from the US Environmental Protection Agency, Appalachian State University and Abt Associates gathered 36 of these US studies into one public dataset and looked for the overall pattern. For water clarity, the most-studied measure, clearer water was linked to higher home prices, with the largest effects in the Northeast. But they also found that using these averages to predict values in a new place can be far off, because the effect depends heavily on local conditions.
What the researchers did
This is a meta-analysis, a study of studies. The goal was to give agencies a defensible way to estimate home-value benefits of water quality policies without running a new study each time, a practice called benefit transfer.
- They screened 65 candidate studies and kept 36 US studies that used objective water quality measurements, dated 1979 to 2017. Most looked at freshwater lakes (24 studies); 6 looked at estuaries.
- They converted each study’s results into a common measure: the percent change in home price for a 1% change in water quality, for waterfront homes and for other homes within 500 m of the water. This produced 656 unique estimates.
- Their statistical models focused on water clarity, measured by how deep a Secchi disk can be seen: 260 estimates from 18 studies covering 66 housing markets. They then tested how well the models predicted results for each market when that market was left out.
What they found
- Clearer water, higher prices. In their basic model, a 1% increase in clarity was linked to about a 0.19% rise in waterfront home prices and a 0.04% rise for other homes within 500 m. A 1% change is small: on average, about 2.34 centimeters, just under an inch, of added visibility.
- The Northeast shows the biggest effects. In the Northeast, the same 1% gain meant about 0.27% for waterfront homes and 0.25% for nearby homes. At the average home price across the studies ($211,314), that is about $559 and $522 per home. In the South, the figures were only $84 and $48.
- Estuaries matter too. For an estuary in the Northeast, the model predicts that a 1% gain in clarity would raise bayfront home values by about 0.35% and other homes within 500 m by about 0.29%.
- Few studies of other measures. Only a handful of studies used algae (chlorophyll a) or fecal bacteria. After weighting for precision, waterfront prices fell slightly as chlorophyll rose, about 0.02% to 0.03% for each 1% increase.
- Big caveats for borrowing numbers. When the models predicted values for a housing market left out of the data, the typical error was 76% to 119%, in the high range for this kind of exercise. The authors also found clear evidence of publication bias, meaning the published studies may not fairly represent all results, and adjusted for it. They call the link between water quality and home values
a very local phenomenon
(Guignet et al., 2022). - A gap between economists and water models. Most home-value studies use clarity because buyers can see it, while water quality models and plans usually track nutrients such as nitrogen. The authors call for better ways to link the two.
What it means for Waquoit Bay today
CPWB argues that cleaner water helps protect shoreline property values in Falmouth and Mashpee. This review of the national research supports the general idea: on average, clearer water goes with higher home prices, and the effects found in the Northeast and around estuaries are among the largest. That is the region and the kind of water body that Waquoit Bay belongs to.
The results come from other places, though, and the authors are clear that averages can miss badly in any one market. They are a reason to take property values seriously; they don’t put a price on Waquoit Bay homes. The paper’s point about measurement also applies here: Waquoit Bay’s cleanup targets are set in terms of nitrogen (see the 2013 nitrogen threshold report), while most home-value studies measure clarity, so translating one into the other takes local data.
Read the paper
Guignet, D., Heberling, M. T., Papenfus, M., & Griot, O. (2022). Property values, water quality, and benefit transfer: A nationwide meta-analysis. Land Economics, 98(2), 191–218. https://doi.org/10.3368/le.98.2.050120-0062R1
License: © 2022 by the Board of Regents of the University of Wisconsin System. Open access under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 (CC BY-NC-ND 4.0) license. The article also states that it was prepared by a US government employee as part of official duties and is in the public domain in the United States. The research was funded wholly or in part by the US EPA under contract to Abt Associates. The PDF below is reproduced unmodified from the publisher, Land Economics. The card image is its first page.
Drafted with AI assistance from the linked source.
