Here is another theory argued by some sociologists, which is even worse: Lack of women is a volatile situation and ripe for crime, war and violence.

Both China and India have large gender imbalances -- and with a border conflict... :-(

"May you live in an interesting time" was a Chinese curse, I think?

There are already many villages in northern India where there are gangs of unmarried men simply sitting there without marriage. Most are uneducated, and have no skills to secure any employment.

Gender related crimes against women already very common in India. I believe they will intensify in the future.

Either way with <850F:1000M gender ratio, for India's population scale there will states full of unmarried men. I believe though crime will be a common place, it won't be possible for all men to indulge in crimes(Which will be a civil war situation at the scale we are talking about).

Either way a lot of men will have to marry men.

You say "have to marry men" like it's a choice to be attracted to the same sex.

IMO it will result in a lot of angry and depressed single men who resent society. If you put someone into a corner without many options they can become desperate and violent. This imbalance in India and China will become very dangerous in the coming years

> You say "have to marry men" like it's a choice to be attracted to the same sex.

Attraction is generally not a choice (there's probably some things you can do deliberately over time to shift it a little bit, but...). Marriage, OTOH, is a choice, and its a choice that historically is motivated by many things, with attraction quite often not being a main factor.

The real problem with "have to marry men" isn't that attraction isn't a choice (as marriage and attraction are not the same thing) but that marriage is not mandatory.