The official U.N. slogan for this year's International Women's Day on March 8 is "A promise is a promise: Time for action to end violence against women." By contrast, the organization International Women's Day 2013 has announced the year's theme as "The Gender Agenda: Gaining Momentum."

Each of those themes is valid but each misses the fundamental point about the role and prospects of women in our time. The two overwhelming facts about women today are that the world is facing a remarkable shortage of females and that they are becoming the better-educated gender.

In 2005, the U.N. population program examined the proportions on women to men in countries all across the world and found that by comparison with the usual male-female ratios, Asia had 163 million fewer women than it should. Repeating that calculation today finds that Asia is short of 205 million.

Mostly this is because of the impact of 30 years of the one-child policy in China. For cultural reasons Chinese families limited to a single child tend to choose a boy and the widespread use of sonograms allows parents to check the sex of a baby in the womb.

The official Chinese figures claim that there at 119 boys under the age of 5 for every 100 girls. Unofficial figures put the ratio much higher.

In 2009, on official data, China had 33.3 million more men than women below the age of 20. The Chinese Academy of Social Sciences reckons there will be at least 24 million more men than women of marrying age by 2020. These men could find themselves without spouse or children.

This affects the labor market, income and consumer spending and is blamed for rising crime rates. China's Law yearbook states that from 1988-2004, criminal offenses rose at an annual rate of 13.6 percent and arrest rates were up 82.4 percent. The overwhelming majority (70 percent) of perpetrators of violent and property crimes in China are 16- 25 years old; 90 percent of all those arrested were men.

Similar trends can be seen across Asia. In India, Pakistan, South Korea and Vietnam there are some 10 percent fewer girls below the age of 10 than there should be, despite laws against the deliberate abortion of girl fetuses. In India, this preference for boy babies is most marked among the Sikh and Muslim population rather than among Hindus.

But just as this shortage of women is developing, women are becoming the more qualified gender. In Europe and North America, for each of the last three years women have won 59 percent of all university degrees and increasingly do so in traditional male preserves like the law, medicine and science.

This isn't just about the developed world. In Iran, Mexico, Brazil Indonesia and Russia women make up 60 percent or more of the undergraduate population. Islamic countries whose ratio of women science graduates exceeds that of the United States are Bahrain, Brunei, Kyrgyzstan, Lebanon, Qatar and Turkey. Morocco has more women engineering graduates as a percentage of the science graduate population than the United States.

These higher qualifications mean sharply improved career opportunities. A survey from Britain's Chartered Management Institute found their average salary of women managers in their 20's was about $32,600 a year, more than $900 more than a man could expect at the same level.

"Approximately 50 percent of women are graduating from university by the time they are 30 and perhaps about 40 percent of men," says U.K. Minister for Higher Education David Willetts. "We've a gap in educational performance that goes all the way through our schools and universities."

And yet across the world, women account for two-thirds of all illiterates. Women in general get paid less than men, get promoted less often and represent only a fraction of top managers and company directors. Not only a waste of talent, this also means the world is a great deal less richer than it could be.

A recent World Bank research paper stated that investing in women's education and bringing women into the workforce at the same rate of men would increase gross domestic product up to 5.4 percent. Surveys in Thailand and Ghana said economic returns from educating girls were 15-25 percent higher than from boys.

One extra year of schooling for girls increases their wages by 10 percent, cuts infant mortality by at least 5 percent and means that all children spend more time in school as a result.

"For those of us committed to addressing global poverty, improving education for girls may be the closest thing to a silver bullet," says MacArthur Foundation President Robert Gallucci.

But it is also worth remembering the story that former U.S. Secretary of State Hillary Clinton tells of the Pakistani mother who had put her five sons and five daughters through primary school, but added, "When our boys finish there they can go off to the secondary school but we cannot let our girls leave the village. It would not be safe."