Discuss why shadow banking should continue to exist.

Write a 5000 words coursework for the title (why shadow banking  should continue to exist) , please divide the research to 5 chapters as following :
1- shadow banking (introduction – definitions – overview )
2- shadow banking in USA .
3- shadow banking in Saudi Arabia (if exists) .
4- research question : why shadow banking is continue to exist ?
5 – conclusion .