A power-differential relationship is one in which one party has structural authority over the other—academic, professional, economic, custodial, therapeutic—and the two are also romantically or sexually involved. The category is ancient and the lines drawn around it are recent. The Greeks regulated certain forms; the medieval church regulated others; American law for most of its history regulated almost none, treating power-differential intimacy as a private matter unless it crossed into clear coercion. The last fifty years have drawn new lines, moving by sector: therapists first, then physicians, then teachers, then clergy, then professors, then bosses, then politicians, then anyone with informal influence over anyone else's career. The lines are still being drawn and the drawing has accelerated.
The conceptual basis is straightforward and contested. The straightforward part is that consent presupposes the capacity to refuse, and structural authority compromises that capacity. A graduate student dating her dissertation advisor cannot freely say no to him; her professional life depends on his continued support, and her saying no would, even in the most ethical advisor's case, alter the relationship in ways that affect her career. This is not the advisor's fault and not the student's; it is the structure. The contested part is how far the analysis extends. Does it extend to relationships between adult professionals at different seniority levels in the same firm? Between a famous person and an admirer? Between a tenured professor and a colleague who teaches in the next department over? The further the line is drawn, the more it intersects with ordinary adult autonomy, and the harder it is to articulate without producing absurdities.
The professional sectors that have drawn the clearest lines have done so in response to documented harm patterns. The American Psychological Association's prohibition on therapist-client sexual contact, enacted in 1977, followed decades of evidence that such contact damaged patients in characteristic and severe ways—loss of trust in helping relationships, deepened original symptoms, sometimes suicide. The medical profession's parallel prohibition followed similar evidence. The clarity in these sectors is possible because the relationship is bounded—it begins at intake, ends at termination, and has formal markers—and because the harm pattern is empirically robust.
The lines outside these sectors are blurrier because the relationships are blurrier. A boss-subordinate relationship has no clear termination point unless one of them leaves the company. A famous person's relationship with an admirer has no formal structure at all. A professor-student relationship ends at graduation, sometimes. The policies that govern these less-bounded relationships have to make judgment calls about scope, duration, and the persistence of influence after the formal role ends. Most policies handle this badly, either by drawing the line too narrowly (and missing real harms) or by drawing it too broadly (and producing rules that prohibit ordinary adult life).
Jennifer Drobac's work on adolescent sexual exploitation has documented a particular failure mode of consent doctrine: the legal apparatus treats a sixteen-year-old's "consent" to sex with a thirty-five-year-old supervisor as legally meaningful when developmental psychology says it is not. The adolescent's brain is not yet capable of the kind of risk assessment that the law presupposes, and the asymmetry of the relationship overwhelms whatever capacity exists. Drobac's proposed remedy—extending the developmental analysis into the law—has not been widely adopted, but the analysis has shifted how some jurisdictions handle age-asymmetric supervisory cases.
The romantic stakes are real. Not every power-differential relationship is exploitative, and some lead to long marriages and good lives. The literature is full of supervisor-subordinate couples who met at work, broke the reporting line, and built durable partnerships. A regime that treats every such relationship as presumptively harmful flattens the moral landscape and produces policies that the workforce sees as absurd. The better regimes acknowledge the real risk while leaving space for the real relationships, which means accepting that lines will be drawn imperfectly and that imperfect line-drawing is better than no lines or perfect ones.
The collective question is what the new lines actually accomplish. The old regime, in which power-differential relationships were unregulated, produced known harms at known rates. The new regime, in which they are increasingly regulated, has reduced some of those harms and produced new costs—chilling of mentorship, displacement of meeting venues, increased reliance on dating apps for adult partner formation. The accounting is incomplete. What is clear is that the regime is not finished and that the next two decades will see further redrawing, particularly around the edges where formal authority and informal influence diverge.