One might think that when men compete for a limited number of women, women’s power and prestige increases. However, sex imbalance often has the opposite effect.  Frequently, it reduces the status of women and girls, as counter-intuitive as that might seem.
For Women: Sex trafficking is the flip side of the gendercide coin. Simply put, there are not enough women for all the men, so men seek out prostitutes. In Asia, girls are kidnapped, lured or sold into prostitution, with local governments making little effort to stop it. Often, local police protect the sex traffickers and frequent the brothels themselves. In addition, an unsavory black market in “brides” develops, with poor women sold to buyers in an arrangement indistinguishable from slavery. Often, brides are imported from other countries, creating a subclass of vulnerable non-citizens with no rights and no access to law enforcement or the justice system.  Often, these women are beaten, abused, and resold to other men.  In certain cases, a poor family may buy a girl to serve as a “bride” (sex slave) to all the men in the household. The world becomes a dangerous place for women, with abduction an ever present risk.17
For Girls: Because women are scarce, bachelors turn to ever younger girls as brides. Young girls are married off to much older men, sometimes even before the girls reach puberty. Once married, these girls have no time for education or paid work. Their older husbands and in-laws, eager for heirs, press them into childbearing as soon as possible. These girls give birth before their bodies are ready, resulting in high rates of maternal death and injury.18
For Bachelors: A surplus population of young men, mainly lower class, develops. These involuntary bachelors never marry, have families, or become part of society. The Chinese call them “bare branches” or “floaters.” In China, these men suffer from higher rates of depression, loneliness, alcoholism, and suicide. While the life expectancy for Chinese men is 75 years, for involuntary bachelors it is just 68 years.19
As of 2020 China has 34 million involuntary bachelors, 24 and India has roughly the same number.24a
Professors Valerie Hudson and Andrea den Boer have found that historically, when large-scale female infanticide occurred in Asia, surplus men formed an underclass of drifting, low paid workers with strong proclivities for violence and crime. When work was unavailable, they plundered the land. Predictably, the “bare branches” spent heavily on drinking, gambling, and prostitution. In both China and India, these historic patterns have re-emerged. Outbreaks of crime, violence, and vice, traceable to unassimilated young men, have erupted in regions where sex ratios are most skewed.20 Overall, crime in China doubled during the twenty-year span from 1995 to 2015, though not all of this can be attributed to the distorted sex ratio. A study by China's Institute for the Study of Labor found that a 1% increase in the sex ratio causes a 5% increase in crime.21 In India, research has shown a striking correlation between sex ratios and murder rates across the states of India. A distorted sex ratio predicts murder rates better than poverty, illiteracy, or urbanization. 21a. Lastly, regional sex imbalance is associated with increases in rape, domestic violence, and use of guns.19
For Society: Social turmoil is a threat in societies with surplus males. It takes nothing more than an economic contraction to ignite the kindling. Historically in China and India, when famine struck regions with surplus males, the young men organized and rebelled, throwing off their overlords and seizing their lands. In China, such uprisings led to both the creation and overthrow of the Ming dynasty.22
Research also suggests that such societies can be governed only by authoritarian regimes.23 If true, prospects for democracy in Asia look dim.
In short, a healthy sex ratio stabilizes a society and makes it a more desirable place to live. There is a very direct correlation between the prosperity of a society and the rights enjoyed by its women.23a