Polygyny and Patriarchy good for women?

In Germany we have famous Rainer Langhans, former boy-friend of Uschi Obermaier of the times of 1968 "and all that", who has his "harem" in Munich even now. One man with three or four women. But everyone has his own houshold and his own freedom to come and to go with whom he or she wants. They're discussing a whole lot about all that between each other - and sometimes in talk-shows - and (I think) they will discuss till life ends. Rainer Langhans has no children. So one more dead end of evolution, that the cultural revolution of 1968 has produced.

But we can observe other social experiments on that line. The current "Journal of the Royal Anthropological Institute" has a review of a book called "Desert Patriarchy" (author of the book: Janet Bennion) about polygyny within the Mormons. And it is said:

... Mainstream Mormons are proud of their polygamous ancestors, but often find the concept repugnant in the present day. Wider secular society tends to associate polygamy only with poverty, ignorance, and child abuse. It is therefore particularly interesting that Bennion has demonstrated the success of such communities in recruiting women from the wider world (Mormon and non-Mormon) to live as plural wives. Such women, she argues, are seeking an escape from the contradictory demands of paid work versus motherhood, from high divorce rates and the associated poverty and isolation of unpartnered women in secular society. They are also seeking a life of spiritual and practical challenge, which offers its own satisfactions. The heavily patriarchal structure of Mormon fundamentalism actually produces communities in which women have an unexpected if ambiguous degree of automony. Since men are outnumbered and often absent, women constitute powerfully cohesive female networks.

And the last sentences:

'Desert patriarchy' closes with Bennion's call, as she contemplates the gains as well as the losses of the patriarchal lifestyle for the women who live it, for social science to acknowledge the complexity in such situations of apparent female subordination. In providing three important case studies in this enterprise, this is a thought-provoking book which will be widely read.

So, nothing is said here about birth-rates.