Big news out of China this weekend: the government is now encouraging couples in Shanghai to have two kids, a reversal of the country’s famous “one-child policy” — the federal mandate instituted in 1979 to control China’s raging population. But with this week’s announcement by China’s Family Planning Commission, something else will be raging: the dormant passion between single-child parents in Shanghai, who themselves must also be only children, who thought they’d never get the chance to conceive again. It’s just so romantic.

The relaxation of the world’s most famous infringement on personal freedom comes not because of any realization by the Chinese government that social engineering is wrong and that Chinese citizens should be trusted to make their own decisions about the size of their families. Rather, China’s leadership is simply tweaking the population engineering formula: as the country’s population is growing older, there might not be enough young people around to care for all the old people. What’s the answer? Have more kids!

As Clifford Coonan reported for the Telegraph Saturday:

The spectre of an ageing population hangs heavy over Shanghai, where the proportion of working adults to retirees is high and threatens a major burden. By 2050 China will have more than 438 million people over 60, with more than 100 million of them 80 and above. There will be just 1.6 working-age adults to support every person aged 60 and above, compared with 7.7 in 1975.

And who wants to live in a city full of old people?

As the goal of the one-child policy was to rein in China’s population, does this new measure signify that China’s population has been reined in? China’s state news agency published the findings of an expert on population growth who believes China will reach zero-growth by 2030. Tian Xueyuan, former president of China’s CASS Institute of Population and Labor Economics, predicted that in approximately 20 years, China’s population will peak at 1.465 billion.

And if China’s population begins to drop within the next two decades, I suppose the Chinese government would have to look at the one-child policy as a huge success — minus the forced abortions, the absurdly out of whack 117:100 male-to-female birth ratio, the abandonment of girl babies, and the infanticide. A huge success, but also a policy that doesn’t seem all that necessary. Another thing to keep in mind is that China’s “population problem” isn’t all that big of a problem. According to United Nations figures taken in 2005, China ranks 75th on the global list of population density — the population of a country compared to the size of that country’s land. For a point of reference, India has 890 people per square mile, while Mainland China has only 360. Hong Kong has over 16,000 people per square mile.

In terms of how fast a country is growing, China is nowhere near the top of that list either (perhaps due to the one-child policy, but who knows). In the 2006 edition of the United Nations World Population Prospects report, China ranked 156th out of 230 countries for rate of population growth, with a projected .58% growth between 2005 and 2010, well below the global average of 1.17%.

So what’s the big deal with China’s population? And why do the people of China not pressure their government to reverse the one-child policy faster? Perhaps this is one of those great China mysteries. Perhaps the Chinese put too much trust in their government. Perhaps Chinese couples don’t mind giving all their love and affection to only one child, a phenomenon that has been labeled the “Little Emperor” syndrome. Whatever the case may be, Shanghai couples should now rejoice in their ability to have another kid, and hope with that second child, brings some sweeping changes to the idea of what a 21st century Chinese family is all about.