“For decades,” according to The Wall Street Journal, “plentiful Chinese labor kept down costs of a range of goods bought by Americans.” Then, roughly in 2010, the Chinese government began supporting higher wages to reduce labor unrest and boost domestic consumption while reducing reliance on exports. Partially as a result of this, the world saw higher prices for commodities in 2011; oil was another factor as protests in the Middle East increased political risk in the calculations of future supply (amid speculation). A shrinking workforce in China was also putting pressure on the labor cost. Even though relatively cheap labor was still in the interior of the country, higher transportation costs mitigated the cost advantage. The prevailing paradigm was showing cracks. To be sure, it certainly had them.
The full essay is at "Economic Imbalances between China and the United States."