For geography, the movement of higher-income residents and business into poor areas of inner cities is generally referred to as

Gentrification is when higher-income individuals occupy lower-income areas. This is often criticized for ostracizing the original inhabitants from their neighborhoods and making the area more expensive to live in.

Explanation:

When reading a story in which the characters do not offer moral complexity, readers do not expect stories to be long. It is expected to find characters with little moral complexity in stories that leave a take away message. However, in novels, the reader expects something more complex. For example, if the story is about a serial killer, it would be good to find, a character who is very intelligent and has a strong family life, but has the underlying and dark life as a serial killer. It is exciting to find a story in which the antagonist is loved and hated at the same time, for example a serial killer who deeply loves his children and his wife. This is that complex characters alleviate contradictions such as the one mentioned above. The person in the story is a serial killer, he is intelligent and has a good family life, those are contradictions that do not make sense for the morality of most readers, they just do not fit into our scheme.