In the case of ecotourism, as indeed in many other areas of endeavor,
the adding up and comparison of costs and benefits is confounded
by the diversity of phenomena to be considered and
different ways each is measured. Thus, economic impacts are usually
measured in units of currency or jobs. Environmental attributes
may be measured through population counts, species diversity,
production of biomass, coliform counts, biochemical oxygen demand,
the presence or absence of indicator species or using a host of
other variables which do not vary together in a linear fashion and
whose significance may be debated by lay persons and experts alike.
Furthermore, there is no widely-accepted way of converting these
into dollars or jobs or, of course, vice versa. Socio-cultural change,
similarly, has a diversity of measures, potentially including such
items as infant mortality rates, proportion of women in the
workforce, or the percentage of respondents answering “perhaps” to
a question on a survey. In such situations it is virtually impossible to
come up with a single summary measure and to determine whether
the benefits exceed the costs.