Unfortunately, economic value is not a fixed, inherent property. Value depends on the nature of the thing itself, its relationship to and with many other things, and with those who evaluate it. 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.