You can't put a price on everything.

The old chestnut about accountants knowing the cost of everything and the value of nothing doesn't sound so funny these days, when the bean counters have more or less taken over the world. The Department for the Environment's National Ecosystem Assessment seems yet another attempt to make real the idea that if it can't be costed it can't be real.

Of course we value some things for their practical use and those things can be priced and exchanged in a market economy; they have instrumental value. Other thing may be valued greatly but we struggle to define that value, let alone put a price on it. Sometimes these two kinds of value come into conflict. We might for example find the view across a valley really beautiful but that aesthetic value may be contested by the need to flood the valley in order to create a reservoir. The people living in the valley can be compensated and resettled elsewhere but there can be no monetary compensation for one's feelings for the valley. There is simply no market in which to trade those feelings. No matter what kind of economic system evolves in the future, disputes about how we manage the environment are inevitable. When considering whether or not to flood the valley we might take into account all kinds of things including loss of farmland and wildlife habitat, the need for water, will a reservoir be for the common good - or just benefit water company profits? We will also consider the sheer pleasure that we get from looking across the valley. It will be a difficult decision to make. But such a decision will not be made any easier by trying to place a completely meaningless monetary value on things that, perish the thought, transcend money.