Dr. Gillian Wylie:

It is very difficult. When I started research in this area, the first thing I discovered was that people come at this from different ideological starting points. If one believes prostitution is always exploitative, it leads one to a certain understanding of the relationship between trafficking and prostitution. If one believes there is more diversity in the situation, one works from a different set of premises. There are some hard data studies that give us the convictions, prosecutions, etc. but they cannot capture the fact that I believe the definition of trafficking, which requires the elements of deception, coercion, movement and exploitation, is so narrow in law that it is very difficult to identify actual victims of trafficking.

Many people who are sadly not considered to be exploited enough in respect of labour or sex are not identified as victims of trafficking. There is a problem with that kind of hard data that only goes to the prosecutions because they do not pick up that breadth of exploitative experience. Where people start from in their imagination regarding the nature of the problem affects what they then count or see. It will be very hard to find really hard evidence.