As a followup on yesterday's note about the roles of women in relationship to this ballad, I wanted to mention an interesting study by Barbara Fass Leavy, called IN SEARCH OF THE SWAN MAIDEN: A NARRATIVE ON FOLKLORE AND GENDER. A good deal of her Chapter 3 entitled "The Devil's Bride" is devoted to "The Daemon Lover"/"The House Carpenter", and she also discusses it within a larger folklore context. She is definitely interested in how this ballad both reflects the feelings and plight of women and also what influence it may have had on both. And her discussion provides a telling critique of the long tradition of male-oriented interpretation of the ballad materials. Here is a link to this chapter:
It is interesting to compare the perspectives of Leavy, Gardner-Medwin, and Heylin. Gardner-Medwin wrote in 1971, Leavy in 1994, and Heylin in 1999. History is never "just history" and the interpretations do change and do depend upon time, place and frame of reference.