Subsistence and Commercial Activities. The Gainj are classic slash-and-burn horticulturalists. They clear land in secondary forest, cultivate plots for one to two years, and then permit them to lie fallow for eight to twelve years, to a maximum of about thirty years. Sweet potatoes are the staple crop; taro and yams also make up a lesser but significant part of the diet. Bananas, sugarcane, breadfruit, pandanus, pitpit, and a large number of domestic and wild greens supplement the basic root-crop diet. Introduced cultigens, such as corn, pumpkins, cassava, papayas, cucumbers, and pineapples, are grown in small amounts. Pigs and chickens are kept in small numbers but are rarely eaten, since they are valued as elements in bride-wealth and exchange. Men do some hunting, but this contributes little to household maintenance. Snakes, lizards, eels, insects, and rats are eaten but their total nutritive value is slight. In 1978, the Gainj marketed their first major coffee crop and are now the major coffee producers for Madang Province. Cash cropping has fostered local business cooperatives which buy and sell coffee beans and operate local stores in which coffee profits are used to buy manufactured items and imported foods such as rice, canned beef, and fish.
Industrial Arts. The most important locally produced items are all-purpose string carrying bags and skirts. Mats and some traditional weapons, spears and bows and arrows, are still manufactured.
Trade. The larger region within which the Gainj live was important in precontact times as a funnel for marine shells (especially cowrie and bailer shells) being traded up into the central highlands, and the Gainj participated in that trade to some degree. In addition, the Gainj area was an important source of bird of paradise plumes for the central highlands. More recently, the Gainj have taken advantage of their fringe highland location by trading lowland cassowaries up to the central highlands, where they are used in bride-wealth payments.
Division of Labor. There is a sharp sexual division of labor. Women bear the major burden of everyday physical work. Women bear, nurse, and care for children; burn, plant, tend, and harvest gardens; provide wood and water; prepare and cook food; tend pigs; manufacture string and weave it into bags and skirts; collect wild foods and raw materials; maintain house sites; and care for the sick and dying. Women also maintain, harvest, process, and carry coffee. Men's labor is more sporadic and dramatic. No longer warriors, they clear and fence gardens, build houses, hunt, plant and sell coffee, and control ritual and politics.
Land Tenure. Gainj say "Yandena ofu" (I make gardens) in a particular kunyung. This applies to kunyung in which they have gardened, are currently gardening, and may garden in the future. Like the Kalam and Kopon, they are unusual in having no corporate groups controlling access to land or exercising rights over land as a group estate. Gainj garden in their own kunyung, in their birthplaces, and in the kunyung or birthplace of any grandparent, parent, sibling, cross cousin, spouse, or child. Access to land is also provided through corresponding spousal relationships. Men and women enjoy access to land and may garden in virtually all of the named territories. While there is no concept of individual ownership of land, for as long as an individual uses land it belongs to him or her, in the sense that he or she has exclusive rights to its produce. Trees can be individually owned and can be passed on at their owner's death. Once a garden has been abandoned, its owner retains no residual rights to it and the land is restored to the common fund. There is always a balance of land being withdrawn from and returned to the common fund. The semipermanent nature of coffee trees will undoubtedly affect further land use and availability.