The original question had to be edited. I think that there is much to find in the novel to suggest that one's construction of "home" is linked to their identity. The ability to find "home" is something that only happens when belonging is evident. This is a state of identity. For characters in the novel, their "home" is where their identity experiences acceptance and belonging. Characters like Jim and Wainwright feel at "home" in the world of Underwood Samson and in a business world where materialism is embraced. This is where their identity feels at home, as it helps to emphasize their belonging.
Erica finds her home in the world of nostalgia. In her relationship with Chris, she finds her home. Her identity can only find belonging in a construction that is impossible to reconstruct. The same edginess that had been her attribute attracting Changez to her is what compels her to believe that her identity cannot find acceptance unless she is back with Chris. Her desire for nostalgia compels her to develop a passionate intensity for a home in which her identity feels comfort. It is a home that cannot be found, something confirmed by her suicide.
No character embodies the relationship between home and identity better than Changez. He believes America to be his home in the outset of the novel because he feels that is where he can find belonging in success, and where his identity will feel at ease. Yet, over time and heightened with the September 11 attacks, it becomes clear that his own identity is not at home in America. The questioning he undergoes in this phase is reflective of an identity that cannot find a home. When America experiences its own "nostalgia" it is a construction of reality that forces a person like Changez out of it. In this, Changez perceives America to be a realm in which there is no home and thus an identity that cannot be at ease within it. In many respects, his embrace of fundamentalism is not out of ideological appreciation or even political reality. Changez embraces fundamentalism because it enables him to find a home, a place where his identity feels validation and belonging. In this, Changez would have to be seen as a "reluctant fundamentalist" because he only accepts it because his identity feels homeless and forlorn. Through such an understanding, it becomes evident that an individual's sense of home is strongly associated with their identity.