Among all the major policy mistakes the Chinese government has made over the last century, I would say the one-child policy hurts the most, much more than the culture revolution, great leap forward, and various others. It is true that over-population can be a problem, but it can be better addressed by sounder policies. It could even be naturally resolved by market economy and Darwinian competition. As evident in other places such as Japan, Taiwan, and Hong Kong, excessive population growth over economic capacity will eventually cause lower birth rate. Forcing every family to have at most one child takes away the natural force of competition, resulting in less fit offspring not only in the Darwinian sense but also other problems such as gender disparity and potential spoils a single child is likely to receive from his or her family.
An even more serious problem is that China’s population growth rate already falls below 2 children per family (see an excellent article here). Population is power, especially in this age of knowledge economy. Japan is a vivid example of how much damage a shrinking population can do to a country’s economy and overall strength. One of India’s main competitive advantages over China is actually its growing population (aside from democracy, English speaking, and friendlier relationships with the Europeans and American, all much more ephemeral factors in my opinion; see an excellent article here).
In some sense, population growth is like monetary growth; neither too much nor too little is good. But deflation is much worse than inflation.
If the Chinese economy follows the path of the Japanese, it will be a disaster not only for China but the entire world. It is time to abolish this communist-era thinking, and write off the one-child policy into the history book.