I've just been looking at the Social Genome Project, work from the Brookings Institute in the US that is "exploring pathways to the American Dream".

The methodology of the work is interesting since it is based on a quasi-longitudinal model using significant datasets. However, the findings will surprise few:

We've identified five benchmarks that are good predictors of eventual economic success: being born to a non-poor, two-parent family, being ready for school at age 5, mastering core academic and social skills by age 11, graduating from high school with decent grades and avoiding risky behaviours during adolescence, and obtaining a post-secondary degree or the equivalent income before age 30.

What is important is what interventions can be made at key points in the life-cycle.