I have noticed a strong tendency among critics to give sole credit to Percy Shelley for works which he co-wrote, and attribute to him works he did not write and

I have noticed a strong tendency among critics to give sole credit to Percy Shelley for works which he co-wrote, and attribute to him works he did not write and could not possibly have written. He seems to be the opposite in this respect to Shakespeare, whose works critics seem eager to attribute to almost anyone else. Mary Shelley was well-educated thanks to her father, who believed strongly in education for girls and ran a publishing house specializing in educational materials for children. When Mary met Percy, she was already an accomplished, published author, whereas he had written nothing of note. When Frankenstein was published, Percy still hadn't written anything but what is today considered juvenilia. The case that Mary helped Percy achieve literary immortality is far stronger that the reverse.