'I was reading somewhere recently (but I forget where) the suggestion that some of the classic ballads collected from the likes of Mrs Brown may have been created by the litterati of that time or not much earlier. (Maybe Steve can amplify?)'

Hi, Richard,
You naughty boy! Apart from the thread drift you are introducing you know very well if we start discussing the latest academic thinking on this one the hot air already being blown is going to turn into a maelstrom.

Instead, take up Jim's very appropriate suggestion and read David C Fowler's brilliant book 'A Literary History of the Popular Ballad' 1968 which to the best of my knowledge hasn't been bettered or criticised. It only goes upto 1800 but very few Child Ballads are post 1800 in origin anyway (IMHO)