By assessing values it is possible to compare trees with cars and labour with buildings and, through this process, assess the merits of different trade-offs. Economic value is a relative concept. It does not deal with absolutes. Ecologists object to the assignment of values for three main reasons. The first is the question of consumer sovereignty.
Market prices reflect the prices that consumers are willing and able to pay.
This assumes that consumers are the best judges of the value and that economy considerations are irrelevant. In these cases, the suggestion is that community values should dominate individual ones and be assessed by political, not economic processes. The second problem that ecologists have with economic value is the apparent assumption that consumers understand the value of the ecological services provided by many biological resources. Ecologists are puzzled by the fact that, whilst they do not know which species play a redundant role and which play a keystone role in most ecosystems, many economic studies appear to assume that consumers, aided by the market place, know which species are not necessary for ecosystem maintenance. The third problem that many ecologists have with the assessment of economic value is that the techniques tend to ignore many equity and moral considerations.