ABSTRACT
A more convenient decentralization is the one commonly assumed in project evaluation exercises. It assumes that there is a single project evaluator evaluating the project over its entire life. This chapter argues that the evaluation of policy changes can be done effectively only with a fair understanding of the way socioeconomic and ecological systems would respond to the changes. Both valuation and evaluation involve comparisons. Evaluation involves the consideration of counterfactuals. The evaluation procedure involves estimating the effect of projects on human well-being. Evaluation of policy changes can be done effectively only with a fair understanding of the way socioeconomic and ecological systems would respond to the changes. Policy changes are perturbations in a prevailing state of affairs. A great deal of work in environmental and resource economics since the 1970s has been directed at discovering methods to estimate the accounting prices of various types of environmental resources.
