Theme: Geography of upward mobility.
Subject Article: "The Neighborhood Effect: Localities and Upward Mobility."
Postscript: Migration (i.e. geographic mobility) begets upward mobility:
“My interpretation of these results leads to a focus on pupil aspiration, ambition and engagement. There is nothing inherently different in the ability of pupils from different ethnic backgrounds, but the children of relatively recent immigrants typically have greater hopes and expectations of education, and are, on average, more likely to be engaged with their school work.
“This is not by chance of course. A key point about London is its attraction to migrants and those aspiring to a better life.”
The good professor's interpretation is backed up by this research on birthplace diversity.