These, however, are obvious targets. What is really intriguing are efforts to value previously ignored "ecological services", both basic ones such as water filtration and flood prevention, and luxuries such as preserving wildlife. At the same time, advances in environmental science are making those valuation studies more accurate. Market mechanisms can then be employed to achieve these goals at the lowest cost. Today, countries from Panama to Papua New Guinea are investigating ways to price nature in this way.

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Item 4 Panama and Papua New Guinea are well established testing grounds for market-based environmental policies.