Customary rights of Japanese village households to use commonly held forests and grasslands, governed since the Edo period by village rules, rotating guards and graduated fines. Recognised in the 1896 Civil Code, iriai commons declined after 1950 through loss of economic value and state policy.
In Japan, iriai refers to the customary right of the members of a village community to use land they hold in common, typically forested mountains and grasslands, for gathering firewood, charcoal, fodder, thatch, leaf litter for fertiliser and wild foods. Most iriai arrangements took shape during the Edo period (1603 to 1867), when villages were the basic units of taxation and administration and rural households depended on the commons for energy and fertiliser. Margaret McKean's studies of three villages (Hirano, Nagaike and Yamanaka) in the 1980s, summarised by Elinor Ostrom in Governing the Commons (1990), made iriai one of the canonical cases of long-enduring common-property management.
Rights belonged to households, not individuals, and only to households recognised as village members; newcomers did not automatically acquire them. Village assemblies or headmen set detailed rules: which areas could be cut, on which days the commons were opened, what tools could be used, how much each household could take and when collective labour was due. In some villages, harvested material was cut collectively and divided by lot. Villages appointed "detectives" who patrolled the closed commons, usually in pairs on horseback; in some villages the post was prestigious, in others all eligible men rotated into it. They fined violators, often in sake or cash, and written codes set penalties rising with the seriousness of the offence, up to ostracism or banishment; guard posts were accountable to the villagers. McKean emphasised that the rules were made and enforced by the users and that sanctions were graduated, two features Ostrom later made design principles.
Modern law absorbed the custom. Japan's Civil Code (1896) recognises iriai rights as real rights in two articles: Article 263, where the community owns the land, applying custom and the rules on co-ownership; and Article 294, where it does not, applying custom and the rules on servitudes. Courts treat the community's ownership as joint ownership (sōyū) by an unincorporated association. In practice disputes are resolved mostly by custom and agreement rather than by the Code.
Under the Edo economy the commons were essential inputs to farming and household life. After the Second World War, fossil fuels, chemical fertiliser and purchased feed replaced most traditional uses, and many communities turned their commons into conifer plantations for timber. Cheap imported timber then undercut that strategy: Japan's timber self-sufficiency fell from 94.5 per cent in 1955 to about 20 per cent from 1995, according to Shimada's study of Yamaguni district near Kyoto. A 1966 law promoting the modernisation of iriai rights encouraged communities to convert collective rights into individual ownership, leases or production forestry cooperatives, on the view that collective management was archaic. By 1990 customary commons covered about 4.6 per cent of Japan's forest area.
The Meiji land survey of the 1870s and 1880s registered forests under individuals, communities or the state; land with no clear claimant, including much former domain land, became national forest, and the government long denied that iriai rights survived on it. In 1973 the Supreme Court held that classification as national land did not automatically extinguish them. Membership rules have also been litigated: in 2006 the Supreme Court accepted a custom limiting rights to household heads but held void, as sex discrimination contrary to public order, a rule excluding women who married outside the village. Newcomers moving into villages near cities raised further questions about who counts as a member.
Iriai commons sustained forests and grasslands for centuries under heavy demand, and McKean found little evidence of the degradation Hardin's model predicts. Their decline after 1950 came less from overuse than from loss of economic value, state policy favouring individualisation and depopulation. Shimada's study of eleven villages found that communities adapted their rules repeatedly, for example by admitting newcomers gradually, but could not counter low-priced timber imports alone, and some abandoned compulsory collective labour after 2003. Neglected plantations now raise new problems of landslides and biodiversity.
Centuries of sustainable use of village forests under local rules and graduated sanctions, recognised as real rights in the Civil Code (arts. 263 and 294). After 1950 traditional uses disappeared, many commons became timber plantations hit by cheap imports, and a 1966 law encouraged individualisation. By 1990 customary commons covered about 4.6 per cent of forest area. Founding year shown is the start of the Edo period, when most arrangements took shape.
In the iriai villages McKean studied, patrolling guards (in some villages a post rotated among all eligible men) enforced the rules, and written codes set fines graduated by the seriousness of the offence; Ostrom counts monitoring and graduated sanctions among the design principles behind long-enduring commons.[1][2][3]
Japan's Civil Code recognises iriai rights as real rights in article 263 (where the community owns the land) and article 294 (where it does not), in both cases governed primarily by custom.[1]
Shimada's study of eleven villages in Yamaguni district found that iriai institutions adapted to newcomers but could not cope alone with low-priced timber imports; customary commons were about 4.56 per cent of Japan's forest area in 1990.[1]