There are different definitions of sex trafficking. The definition given in the Palermo Protocol, more specifically with respect to taking a person from one location to another or from one country to another by using stratagems such as coercion or deceit, which victimizes people.
As part of its work, the sex trafficking research group has become aware that even this definition, when it comes to applying it, has quite a few limitations. Indeed, how can one determine whether there has been deceit, for example? It is not obvious. We know that in cases of international trafficking, at least, the women involved wanted more than anything else to leave their country and found themselves in a situation in which they were illegal immigrants. This obviously does not encourage them to inform on their traffickers, because that would advertise the fact that they themselves are here illegally.
It is very complex. In any definition of sex trafficking, the concept of exploitation needs to play a much bigger role.