Exploitation and the Vulnerability Clause

What conditions of vulnerability must an individual face in order that we might ever correctly say that she or he has been wrongfully exploited? Mikhail Valdman has recently argued that wrongful exploitation is the extraction of excessive benefits from someone who cannot reasonably refuse one's offer. So, 'being unable to reasonably refuse an offer' is Valdman's answer to this question. I will argue that this answer is too narrow, but that other competing answers, like Alan Wertheimer's, are too broad. I propose a new answer, a "vulnerability clause" to partially comprise a theory of wrongful exploitation. In so doing, I appeal to Marilyn Frye's account of oppression and take guidance from her inclusion and exclusion criteria.