A 'Safe Minimum Standards' approach to environmental protection repres
ents a supplement to cost-benefit analysis which places greater emphas
is on the protection of the environment wherever thresholds of irrever
sible damage are threatened. It is based on the rationale of minimisin
g maximum possible losses so long as the social costs of doing so are
not 'unacceptable'. However, the concept of Safe Minimum Standards has
been otherwise interpreted as justifying an abandonment of the need t
o quantify benefits deriving from preservation of the environment. It
is frequently claimed that it is the opportunity costs of preservation
,-i.e. the benefits of a proposed development-which represent the soci
al costs of imposing a Safe Minimum Standards decision rule. Such a pa
rtial opportunity costs approach is not only contrary to the original
concept, but may serve only to justify accepting the largest, and poss
ibly most environmentally damaging, development projects. It is theref
ore also likely to produce recommendations that are contrary to what m
ost proponents of the Safe Minimum Standards approach would endorse. I
nstead, it is proposed that SMS should be interpreted as favoring pres
ervation in the face of irreversible environmental damage, unless the
social costs of forgone development-defined as the benefits of develop
ment net of the expected benefits of environmental preservation that w
ill be lost-are unacceptable. In this way, it can serve to moderate re
commendations formulated according to underlying economic efficiency c
riteria, with respect to other, perhaps conflicting, social priorities
. (C) 1998 Elsevier Science B.V. All rights reserved.