This paper summarizes in non-technical terms the economic case for conserving biodiversity, and explains why we cannot rely on market forces to do this task. It reviews the policy interventions that could help in biodiversity conservation

Biodiversity provides essential services to human societies. Many of these services are provided as public goods, so that they will typically be underprovided both by market mechanisms (because of the impossibility of excluding non-payers from using the services) and by government-run systems...