The economic value of the Upper Tuul ecosystem in Mongolia reports on a study carried out under the auspices of the World Bank and the Government of Mongolia. The goal of the study was to improve understanding about the economic value of the Upper Tuul ecosystem for Ulaanbaatar's water supplies and how this might be affected by different land and resource management options in the future. The study also aims to develop and apply ecosystem valuation methods that can be used more widely in the country, to generate information about the contribution of the environment to the Mongolian economy, and to make the case for improved budget allocations for the conservation of the Upper Tuul. Integrating eco-hydrological and economic valuation techniques, the study traces through the biophysical effects and socioeconomic impacts of future land and resource degradation, and ecosystem conservation, in the upper watershed.