Final answer:
The study of different marital household structures reveals that economic strategies, cultural practices, and child-rearing costs influence marriage forms, with polygamy prevalent in agrarian societies and monogamy common in Westernized contexts where economic demands lead to dual-income households and higher marital instability.
Step-by-step explanation:
The study of one-wife vs two-wife vs three-wife households shows that social, economic, and cultural factors greatly influence marriage practices and family structures. In cultures where large-scale farming is prevalent, such as in certain areas of Africa and the Middle East, the polygamous union of a man with multiple wives can provide an advantage in terms of manpower for labor-intensive agricultural tasks. Polygyny is more common in these environments as children contribute significantly to food production and household labor. Conversely, in the United States and other Western societies where children are not seen as economic contributors but rather require substantial investments, the structure of households tends to favor monogamy, with rising trends of serial monogamy and dual-income households due to economic demands and labor participation of both partners.
It's also worth noting that while polygamy is legally and culturally accepted in some societies, it is practiced by a minority – often wealthier and of higher status – and tends to decrease with urbanization, access to mass media, technology, and education. As for the economic implications of marriage in contemporary societies, there has been a shift from single-earner to dual-earner households, with a trend toward marriages between high earners which has further implications for economic inequality and household dynamics.