Ostrom showed villages govern commons better than states or markets

Orthodoxy held that shared resources were doomed: the tragedy of the commons prescribed privatization or centralized regulation as the only cures. Elinor Ostrom, a political scientist at Indiana University, tested that prescription against reality — decades of studies of user-managed fish stocks, pastures, woods, lakes and groundwater basins.

The findings reversed the doctrine. Outcomes, the Nobel committee noted, were more often than not better than standard theories predicted: resource users frequently built sophisticated mechanisms for decision-making and rule enforcement that handled conflicts of interest without either a leviathan or a land registry. In 'Governing the Commons' (1990) she characterized the rules that promote successful outcomes, turning institutional folklore into a comparative research program.

The Royal Swedish Academy awarded her the 2009 prize in economic sciences — the first woman to receive it — shared with Oliver Williamson, whose theory of the firm's boundaries mirrored her theme: economic governance happens in institutions that are neither markets nor ministries, and can be studied with the same rigor.

Let the users write the rules

The binary of privatize-or-regulate was an untested assumption; field studies replaced it with an empirical question.

Users with long horizons built monitoring, graduated sanctions and cheap dispute resolution that outsiders could not replicate.

Evidence that common property outcomes beat theory's predictions forced the discipline to expand its model set.

Characterizing which rules succeed made commons governance teachable instead of folkloric.

Before choosing between market and state, ask who already lives with the resource. Local rule-writing, monitoring and graduated penalties are a third institution — often the cheapest and most durable.

Ostrom's rule-based approach now informs fisheries, forest, irrigation and water policy worldwide, and the Workshop in Political Theory and Policy Analysis she co-founded at Indiana in 1973 carried the research program forward. She died in Bloomington, Indiana, in June 2012, having become the first woman to win the economics prize.