2) It is not explicitly listed who sponsored this research, but presumed Standard Chartered
3) The sponsor of this study would very likely have an interest in the outcome of this study since they are a financial institution that profits from financing trade between Europe, Asia and Africa.
4) 87 manufacturing firms were surveyed during the first quarter, it doesn't say if the sample is random
5) The results are clearly indicated within the text, however not broken down to show the number of firms within each wage percentage increase
6) There are no graphs in this study
Heard on the Street: Exporter's Gain Is Workers' Loss in China's Labor Force
Wall Street Journal Online