Like any other policy, environmental policies should be carefully assessed both prior to their implementation and after they have been in place for some time. In-depth evaluations require that a value has been placed on the benefits that environmental policies provide, so that they can be compared to the costs of the policy using a common metric.

OECD has done, and is doing, much work to help in this regard. A major report described recent developments in cost-benefit analysis and reviewed conceptual and methodological developments in this area.

A major part of the benefit of many environmental policies (e.g. regarding local air pollution and water pollution) is reductions in human mortality. It is hence important to place a value on the lives that these policies save – a Value of a Statistical Life (VSL). To help countries get a stronger basis for doing so, OECD is doing a meta-analysis of all available VSL estimates based on surveys where people have been asked what they would be willing to pay to reduce mortality risks in an environmental, health or traffic context.

OECD has also prepared a review of estimates where people have been asked how much they would be willing to pay to reduce non-mortal environment-related health risks and reviewed the recent empirical literature relating to the quantification and valuation of the human health impacts of air pollution, hazardous chemicals, and unsafe water and sanitation, and their use in cost-benefit analysis.

Valuation of environment-related health impacts for children poses a number of particular problems that OECD’s  sought to address. This involved the implementation of surveys in three OECD countries (United Kingdom, Italy, Czech Republic) by leading experts in the field of health valuation.