“…The first concerns the fact that, as de Groot (1992) pointed out, "for some information functions such as the esthetic and spiritual value of nature, monetary evaluation is a difficult if not impossible procedure." Over the last two decades, this same comment has been made numerous times (e.g., Rolston, 1985;Chee, 2004;Chan et al, 2012a,b;Kirchhoff, 2012;Setten et al, 2012;Parks and Gowdy, 2013;Winthrop, 2014;Boeraeve et al, 2015;Walter et al, 2015), with no clear solution in sight. There is definitely a risk in this respect that if monetary valuation becomes a standard step in the management of environmental resources, all the functions and services that cannot be monetarized will simply be ignored.…”