Here's an article about the male/female imbalance in Mormonism and orthodox Judaism. The author says the problem for Mormons is increasing rates of male apostasy. However, it's not just within religious communities that the problem exists, as witnessed by the universal blight of "hook-up culture." Americans are increasingly likely to only marry their like, increasing income inequality. Women with educations aren't marrying men without educations, and women are progressively more educated than their male peers. I remember an article from National Review sometime between 2005 and 2009 (I remember it was while I lived in Kansas) about boys getting treated as "adults" by their parents sooner, meaning they were responsible for financing their own educations, so they were attending college less frequently. Less-educated boys and more-selective girls will create a marriage problem in any group; throw in the apostasy issue and you have what Time calls a "crisis."
One ramification of this issue is changing attitudes towards sexuality. Faithful single members who follow church teachings about sexual activity face what Daniel Klein has called "demeanedization," meaning they demean themselves. Jennifer Finlayson-Fife has spoken about the problems that come from this type of perpetual adolescence. How can we deal with an existence that gives all of us a sexual impulse (Emily Nagoski would not like it if I called it a "drive") and requires us all to learn to live with it, but gives some of us opportunities to learn and some of us get told "ignore it"?
I have some thoughts about this that are probably too personal for any of you to feel comfortable reading, so I'll just stop there, I guess. They deal with the distinction between what is taught as acceptable and what my personal experience has lead me to believe is acceptable, and why they might differ.
Of course, a continuation of this sex imbalance (I hate using the word "gender" to mean what the word "sex" already means) might look like justification of polygamy, which is a crazy-loaded issue with Mormons. It might be of interest for some to find out that there are plausible explanations of early polygamy that are not as troubling as some of the more-commonly accepted explanations. [UPDATE 10/22/15: A critical response to the explanation found at that link can be read here.] Of course, evidence is lacking, so it's really a question of how much benefit of the doubt do you want to give the old timers. I just want to draw attention to the fact that earliest polygamy maybe didn't involve anything untoward, so a resumption might not be as trying as believed.