People who live in affluent neighborhoods such as Northwest Washington may wonder: Will it hurt my kid’s chances of getting into Harvard if I let her stay in the public schools after elementary school?

Local elementary schools such as Murch and Lafayette have nearly all children of college-focused parents and excellent achievement results. But Deal Middle School and Wilson High School are more economically diverse, leading some to doubt that the learning standards will stay high.

I have met parents pondering this issue in many parts of this region and the country — in Alexandria, Silver Spring and Reston; in Hillsborough, Calif.; White Plains, N.Y.; Aurora, Ill.; and Dallas.

It makes for good Sunday barbecue chat because there are no available data favoring either side. So I was shocked when Northwest Washington resident and health-care technology analyst Leonard Jewler told me he had all the numbers and was ready to settle the argument.

Jewler has worked on this personal project for five years, since he realized that the 2006 reunion of the Lafayette Class of 2000 allowed him to find out which of those students went to private high schools, which went to public high schools and which colleges enrolled them.

In 2007, he shared his first results with my colleague Marc Fisher on his Raw Fisher blog. About a third of the Lafayette students went to private high schools, a third went to public ones and the other third could not be reached. Fisher noted that was too small a sample for any statistically valid conclusions, but the results were still interesting:

“The kids who went to the top state universities — places such as Berkeley, the University of Michigan and the University of Virginia — seemed just as likely to be graduates of public high school as private high school,” Fisher wrote. “Turn to the top-ranked private universities and the survey reaches the same conclusion. An equal number of Lafayette kids who went to public high school and Lafayette kids who chose private high school ended up at universities in the top percent on the U.S. News list — Yale, Stanford, Vanderbilt, Georgetown among them.”

This doesn’t surprise me, because of a leveling mechanism employed by selective colleges. If you have straight A’s, a solid SAT score of 2200, and good activities and recommendations, your chances of getting into an Ivy League school are better if you are attending an average public high school than a competitive private one. As City University of New York Graduate Center scholar Paul Attewell showed in a 1997 study, more people will apply to selective colleges from competitive private schools than regular public schools, and selective colleges will take only a few from each school.

Jewler has a new study showing once again, with a much larger sample of 336 students, the graduating classes of Lafayette and Murch from 2000 to 2004. There are intriguing details, such as the exact number of students from these two elementary schools who enrolled in each college.

Here are the results for some of the more famous colleges, giving the number of public and private high school graduate enrollees. Jewler’s Web site has the full report.

Brown: 2 public, 3 private; Columbia: 1 public; Cornell: 3 public; Dartmouth: 1 public, 2 private; Harvard: 4 public; Princeton: 1 public, 2 private; Stanford: 3 public; Vanderbilt: 1 private; Yale: 5 public, 4 private.

I suspect the numbers look similar in other such neighborhoods around the country. As Jewler notes, graduates of elementary schools such as those have family support that leads to college admission success no matter where they go to high school. Public or private, if they listen to their teachers, do their homework and pursue an interest or two outside of class, they will find a great college glad to have them.