Jim,
We have to agree to differ. I'm simply going by majority vote looking around my library shelves at the titles of the books. I have just about every anthology of ballads, English, Scots, Irish, American available on the market; Roxburghe Ballads, Ancient Ballads traditionally sung in New England, Ord's Bothy Songs and Ballads, Ballads of the Pubs of Ireland, The Pepys Ballads, Songs and Ballads of Dundee, the Ballad Minstrelsy of Scotland, Border Ballads, The British Broadside Ballad and Its Music, Child Ballads, Bawdy Ballads etc.

Admittedly many of them have 'Folk Song in the title' but then Ballad in this case is a category of folk song.