In that particular study, the statistics that Alison cited in saying that the wage gap is half as large within a workplace as it is economy-wide used information from our workplace and employee survey, and that was circa 1999 or so. In that particular one we used workplace size and industry as control variables. There are other workplace characteristics. I'm just trying to remember what they all were. I didn't go over that particular study because it was a bit older. There was a non-profit flag. I do think there was something to do with different compensation, such as bonuses and what have you, but that was mostly when I was able to control for the workplace.
Most of these studies cited here always believe that wages are tied to the individual worker and not necessarily to the workplace. That was the first Canadian study that brought in the workplace characteristics.