Of the five recognized forms of marriage in Kenyan law, three are monogamous - Christian, civil, and Hindu marriages. Islamic marriages are potentially polygynous, and African customary marriages are polygynous. Although the precise word for marriages of single husband/multiple wives is “polygyny,” Africans use the broader term “polygamy,” and it will be so used here.
A man may take junior wives only if he is able to support them, which limits polygamy. Bride wealth alone inhibits polygamy, but the increasing cost of educating children is equally daunting. A man may take a second wife as a display of wealth or prominence, to provide an assistant in farm work for the first wife, or to begin another family. Each wife has to have living quarters for herself and her children. In practice, men arrange a small plot of land that the wife works to support the children.
A polygynous husband is expected to be sexually active with all his wives. In some groups, she is entitled to a visit between each menstrual period. More commonly in the rural areas, a man will sleep with his wives in rotation, several weeks at a time.
In contemporary society, the husband may take a job in the city, and visit his wife or wives from time to time. It is not uncommon today for a man to live apart from his legal wives for many years in this way.
In some cases, one or more wives may live on the shamba, or garden plot, while another stays in the city, caring for her husband. In addition, many men will take a “city wife,” a form of concubinage in which the man supports the woman in the city while not having a legal relationship with her. Many wives, living on the shamba, prefer this to another legal wife or the probability of her husband’s resorting to prostitutes. Children born to a “city wife” are the father’s, and are raised by his wife.
Polygamous marriages were never in the majority, and today are declining under economic pressures. At the same time, other, less formal arrangements have become common. These include the phenomenon of the “city wife” and polyandrous mistresses. This latter arrangement involves several urban men who jointly support a woman. None of them live with her, but she shares a sexual relationship with each. In one case known to the author, one man paid the woman’s rent, another her food bills, and a third paid for her clothing. Her arrangement was known to her peers since she held a professional position, and she was not regarded as a prostitute. Any children born of such arrangements are regarded as fatherless. [I am not aware of this polyandrous relationship involving a wife openly maintaining a sexual relationship with two or more men. However, a wife or mistress may have sexual relationships with more than one man, for the purpose of obtaining money from each. When the men eventually learn about the multiple relationships, the result is a breakup that may escalate with a thorough beating of the woman or fighting between the men involved. (Kariuki)]

The addition of a second wife to a household illustrates how conflicting interests between household members can lead to rigidity in some cases and adaptability in others, depending on the perceived costs and benefits to individual household members. Evidence from several sub-Saharan African countries in which polygamy is still widespread shows that first wives tend to accept the second or third wife because they perceive several advantages and not only disadvantages. This adaptability is predicated on the fact that first wives (particularly in rural areas) have a very heavy workload, and they welcome labor sharing with the second or third wife (McSweeney, 1979). This is especially true when wives\' land plots are large and productive enough to feed their own children and to yield a potential surplus. Thus, first wives adapt to a structural change that decreases their access to their husbands\' love, sexual favors, labor, and income contribution because they gain in terms of time for their own sleep, labor, and a certain degree of autonomy in terms of being able to control the money they earn and to get involved in marketing away from home (Safilios-Rothschild, 1983). In some provinces and countries in sub-Saharan