I don't understand how the one-child policy is reducing the number of young workers so much that it would effect wages so dramatically, especially in light of the large surplus of rural labor. In 1980, when the policy was introduced, China has a population of just under 1 billion (981 million according to World Bank figures). Now, it's more than 1.3 billion (1327 million, according to Wikipedia). That's an increase of 346 million, or 35% over the last 28 years.

I understand that this represents a decrease in population growth rates, and higher standards of living are likely increasing life expectancy. But for a policy designed to stabilize and then decrease population, "one-child" in China appears to have failed almost entirely.