The fraternal polyandry marriage relationship of Tibet is widely consideredto be a means of preventing the division of a family\u27s resources among its male heirs. As a family resource preservation strategy, Tibetan polyandry accomplishes the same goal of the European stem family system, but in a very different way. Researchers have suggested that polyandry developed in Tibet, because it provides a household with enough male laborers to fully exploit the marginal agricultural lands in the Himalayas, that it serves as a means of population control, or that it serves as a way of reducing tax obligations to feudal Tibetan lords. A more convincing explanation why Tibetan polyandry is practiced is provided by Nancy E. Levine. She claims that polyandry provides a household with a large labor force, enabling the family to pursue simultaneous and extensive involvement in the three different sectors of the Tibetan economy: agriculture, herding, and trading (1988). Since Tibetan polyandry provides such important economic advantages to households, one can assume that the reasons for the dissolution of polyandrous marriages are largely for individual interests. Levine (1981) and Melvyn C. Goldstein (1981) find that the breakup of polyandrous marriages is usually caused by the younger brothers of the household, because of unhappiness with their spouse, their lower reproductive success than older brothers, a desire for personal autonomy, and difficulty in maintaining a large household. Goldstein (1981) also finds that brothers are more likely to leave polyandrous marriages when unexpected economic opportunities arise
