In the US, the Education Longitudinal Study of 2002 selected a "nationally representative cohort" of 10th grade (~16 year old) students in 2002 and followed up on them in 2012 to see how far they had gotten. This study quantified economic status by equally weighting "their parents' occupation, highest level of education, and income."
The results are here, but the bottom line is that:
- for those in the top quartile, 60% got a bachelor's degree or higher
- for those in the bottom quartile, only 14% did.
This is a well-regarded study, and the results are striking. My concern with this analysis, however, is that you asked about "wealth," but income comprises only 20% of this study's "economic status" variable. The rest of it takes into account the parents' educational status and careers. So, unemployed parents with tons of student debt could conceivably end up in the top quartile, while rich parents without a college degree could end up in a lower quartile.
This New York Times Article shows a simpler analysis: college attendance vs. parents' income percentile. This blog post redraws the curve showing college attendance vs. income in dollars. The latter is particularly striking:
- For family incomes of $50K, ~40% of children attend college (the exact number is a little hard to read on the graph).
- For family incomes of $200K+, ~90% of children attend college.
It's not possible to infer causation from this: did the extra money open doors directly (e.g., for tutors, private schools, fancy summer programs)? Or is there some other explanation (e.g, that parents whose parenting style engenders college attendance also tend to be rich)?
More broadly, questions like this are plagued by the definitions:
- How do you quantify "academic performance"? Grades? Test scores? Merely attending college, as in the study above? Any proposed definition will attract criticism.
- Defining "wealth" is a bit more straightforward, but still challenging. Income alone overlooks several complications, such as debt and the local cost of living. Total net worth has similar challenges.
Hence, it's unlikely that any number from any study would be universally accepted; the two studies listed above seem to be the best that we have.