John Loomis is an American economist known for his work in environmental and resource economics. He has contributed significantly to the understanding of how economic principles can be applied to natural resource management and environmental policy. His research often focuses on valuing non-market resources, such as clean air and water, which are essential for sustainable development. Loomis has published numerous articles and studies that explore the economic impacts of environmental changes and the benefits of conservation efforts. He is also recognized for his role in developing methodologies for assessing the economic value of ecosystem services, which helps inform policy decisions related to natural resources and environmental protection.