Ayup.. government gets involved (China) creates a massive problem... that only government can solve. Well that's the theory. Another theory would be instead of giving government the power to fix their screw ups... getting government out of the business of regulating our personal relationship decisions.So much depends on demographics.
In most countries the male/female ratio manages to balance itself out (though not perfectly) all by itself.
In India and China there are wide disparities as gender selective abortions are common. Indeed, in China, almost the norm because of now fading but still existing "one child" laws. In Japan the disparity is not in raw numbers but is attributed to educated women eschewing marriage altogether!
It has been shown that in cases of wide disparity with a surplus of males prostitution becomes rampant and crime, particularly rape and abuse, get out of control.
Stretch your mind to the fullest extent your party allows. Can you imagine a society in which plural marriage (one woman, two or more males) are not just accepted but encouraged or mandated?
Before replying, please re-read the paragraph immediately above and consider whether you're up to the challenge.