Polygamy...render low-status men ...unmarriageable

.... a practical observation. Polygamy tends to render low-status men completely unmarriageable,
and their access to women is usually restricted, if not eliminated altogether.

It is difficult to say what precise effect this would have in a modern, Western culture, but while it could have some positive effects with regards to crime and other ills,

it is also theoretically capable of creating a persistent underclass even more prone to destabilizing behavior than before.
http://www.voxday.net/archive/2005/101705.html

SEE MY OTHER POST ON ALPHA MALE