PRC Government numbers: http://www.tradingeconomics.com/china/wages-in-manufacturing http://www.marketwatch.com/story/china-wages-jump-in-2012-de...
WSJ: http://online.wsj.com/news/articles/SB1000142405274870384920...
Journal of Economic Perspectives: http://leedsonfinance.com/2013/02/24/the-end-of-cheap-chines...
No one source is believable but there appears to be wide consensus here. Also note these are real, inflation-corrected wages. You can tell especially by the WSJ's concern over prices, if inflation explained the changes it wouldn't impact export costs which are priced in USD not Yuan.