Water, lumber

Usable water is like other resources in being a product of human labor and ingenuity. People "create" usable water, and there are large opportunities to discover and utilize new sources.

Water for residential use will never be a long-run problem in itself because even at the cost of the most expensive means of production--desalination--the cost of water used by households is small relative to households budgets in rich countries. The desalinated price may be much less as tech improves and the price of energy falls. Furthermore, homes reduce their use of water as the price goes up.

The most important fact for consumer water supply is that most water is used in agriculture. The reason that there are cases of absolute shortage and rationing is that price is not allowed to respond to market conditions, but rather is fixed at a low subsidized price in many agricultural areas. Another difficulty is that agricultural and municipal rights to use water from rivers are complex legal structures that often do not fit modern needs.

Many trees are planted in order to be cut down--especially for paper. Indeed, 87 percent of all paper in the United States is produced from trees planted and grown for that purpose by the paper industry.

Why does the public believe that forests in Europe are declining when they are actually increasing? Part of the explanation is that researchers invalidly infer general effects from partial biological data.

More lumber is purposely planted. Higher productivity enables an increasing number of trees grow on a shrinking area. Conservation efforts due to higher prices, and research on wood and wood substitutes.