From the introduction to the volume:
Although the popularity of the Twilight franchise in the early twenty-first century brought Young Adult (YA) Romance to public attention, Amanda Allen’s chapter ( Chapter 7) on this subgenre demonstrates that critical debates over fiction written for young readers—especially young women—have existed for many decades. Allen divides her history into three periods: work from the 1940s–60s, when it focused on the socialization of young women through what were called “junior novels” (tales of young love set mostly in American high schools); scholarship from the 1980s, which often including feminist critiques of the same socialization practices lauded some decades before; and scholarship since 2000, which addresses paranormal YA romance, queer and otherwise diverse YA romance, and non-traditional forms of YA romance publishing, including fan fiction and romance in visual media (e.g., graphic novels and manga). (14)
Unlike other types of popular romance, what defines young adult (YA) romance is its audience. This statement is obvious, but it also masks a complicated set of conventions and assumptions that reflect changing ideologies concerning our collective notion of “teenagers,” and what constitutes “appropriate” reading material for them. Whether one examines YA romance as a subgenre of adult popular romance, or as a sub-genre of young adult fiction, most critics recognize the power imbalance between adult producer/distributor (author, editor, librarian, teacher, parent, etc.) and reader (assumed young person), which is inherent to these texts. In some ways, then, scholarship on YA literature—of any genre—is always about power, and analyses of YA romance are no exception. (168)
How will a focus on age continue to expand definitions of “popular romance,” particularly considering that a focus on youth necessarily negates the presupposition of a long-term Happily Ever After? (185)
I include that last quote because I have noticed with regards to classification that in the area of YA/teenage romance, the word "romance" does seem to be used in a broader sense than in scholarship about adult romance.