This paper examines the effect of properties being located in vulnerable zones in
term of nitrates on the property prices using a change in the classification of vulnerable
zones in France in 2012. Using an identification strategy based on a spatial difference
in-differences specification, we show that the revision of the classification significantly
decreased not only property prices in zones that became classified as vulnerable after
the revision, but also those of properties already classified as vulnerable. However,
the effect was stronger for the former, 10% vs. 5%, and this differences may reflect a
difference in how zones are classified. The risks covered in the 2012 classification cover
a broader range of risks, and hence the larger price effect may reflect this additional
perceived risk exposure.