Ostrom's research focused on the ways in which common-pool resources, such as fisheries, irrigation systems, and grazing lands, can be managed and governed effectively. She argued that common-pool resources can be successfully managed by local user groups, rather than being subject to overuse and depletion, as was commonly believed at the time. Ostrom's work challenged the traditional view that common-pool resources can only be managed effectively through centralisation or privatisation, and showed that local institutions can play a key role in their governance.