What are some possible explanations for the rise of the novel as a new literary form?

The rise of the novel as a literary form, at least in
England, is often associated with the following
phenomena:

• The rise of the economic and social
  power of the middle class and the slow loss of such power by the aristocracy. Novels
  increasingly came to depict, in realistic terms, the behavior of people who were neither
  fabulously wealthy and immensely powerful nor exceptionally poor and powerless.
  


• As more and more middle-class people became literate and
  had money to spend on works of fiction, more and more novels were written to satisfy
  their tastes for reading about people who often resembled
  themselves.


• The rise of increasingly large cities meant
  that social interactions with large numbers of other people were increasingly common.
  The novel helped explore the place of individuals in a complex social
  world.


• The rise of individualism, in which people
  increasingly had to make choices for themselves rather than having their lifestyles
  dictated to them by longstanding traditions, meant that more and more people were
  interested in reading about individuals and the choices those persons had to
  make.


• The rise of individualism also helped encourage an
  interest in the complexities of individual personalities and characters. To the extent
  that the novel has a strong psychological dimension, it was responding in part to the
  increasing emphasis on the idea that each human being is unique and has a mind of his or
  her own.

Many of the traits just described are
visible in the opening paragraph of Daniel Defoe’s book Robinson
Crusoe, often considered one of the first novels in
English;

I
was born in the year 1632, in the city of York, of a good family, though not of that
country, my father being a foreigner of Bremen, who settled first at Hull.  He got a
good estate by merchandise, and leaving off his trade, lived afterwards at York, from
whence he had married my mother, whose relations were named Robinson, a very good family
in that country, and from whom I was called Robinson Kreutznaer; but, by the usual
corruption of words in England, we are now called—nay we call ourselves and write our
name—Crusoe; and so my companions always called
me.