While America's rich are getting richer, evidence seem to indicate they are getting smarter—or at least better in school—as well.

Nationwide, until around 1980, middle- and upper-income students performed at around the same level in schools. The gap that existed then was between them and students from low-income families.

Now, though, rich students have pulled away from the middle-income ones—as far away as middle-income students are from their low-income counterparts.

"Just as the incomes of the affluent have grown much more rapidly than those of the middle class over the last few decades, so, too, have most of the gains of educational success accrued to the children of the rich," Sean Reardon, a Stanford professor who's documented this trend, has written.

Reardon lays much of this squarely on the increase in income inequality, which has left rich parents with "far more resources, relative to low-income families, to invest in their child's development and schooling."

"We're expecting some kids to start on a broken stairwell, others on an escalator and some on a bullet-like elevator" and all of them to reach the top, Prudence Carter, also of Stanford and co-editor of a book entitled "Closing the Opportunity Gap," said last spring.

It’s a familiar story in New York where affluent families spend lavishly on educational services barely heard of a generation ago: tutors earning in the triple digits an hour, pricey test prep programs and private school and college admissions coaches, to say nothing of thousands of dollars for special classes, summer programs and foreign tours.

Many experts say income, more than race, now accounts for the so-called "achievement gap" in the U.S. But the picture in New York City is a bit more complicated. Although former schools chancellor Joel Klein often said students' success should not be determined not by "the color of their skin or their ZIP code or even their parents’ income," race, residence and income inequality all overlap to create huge differences in how well—or how poorly—children fare in the classroom

What $40,000 buys

The richest students in New York do not show up on most education indicators. They attend private schools, where tuition hovers around $40,000 a year and many parents give upwards of $25,000 a year more.

What do they get for that? Small classes, teachers with advanced degrees and lots of frills. The web site for Léman Manhattan Preparatory School highlights its aquatics center, rock climbing wall and "café run by professionally trained chefs." Packer Collegiate Institute in Brooklyn reportedly has an information technology department with three people who do nothing but fix broken laptops. Attempting to explain why tuition has reached such rarified levels, the New York Times described one school with "three theaters, six art studios, two tennis courts, a pool and a diving pool" and another with a $2 million learning center with "six full-time employees offering one-on-one help with subjects as varied as note-taking and test-taking."

While the children of the 1 percent have guidance counselors negotiating with college admission offices on their behalf and sample classes such as Zen dance and advanced Mandarin, the city's poor and middle-class students spend their days in a different universe. Even the best public high school in New York City has classes with about 30 students. Halls can be noisy and even chaotic as classes change, and with the move to smaller schools, academic offerings may be limited to a single foreign language, say, or chemistry but not physics. Musical instruments and arts supplies can be scarce, if they exist at all.

Improving the odds

Many parents not in the 1 percent still have money to spend on their child's education; one thing they spend on is test prep—even for the youngest ones.

Ever since the city instituted a test to determine admission to elementary school gifted and talented programs, parents wanting to get their child in the elite and free classes have hired tutors and sent their children, as young as 4, to programs—one dubbed a "boot camp—aimed at improving their odds on the test. Last year, the Department of Education changed the test to one they said would be less vulnerable to test prep. Worried parents still scooped up copies of test prep material costing $149 and flocked to tutoring programs. "They can keep switching tests from now until doomsday and it's not going to make a difference," said James Borland, a professor at Teachers College at Columbia University, told the Wall Street Journal.

Borland and other experts generally believe that any single test tends to favor students from more advantaged backgrounds. Giving the test to such young children only magnifies that result as a child who has had test prep and gone to a high-quality preschool program will almost certainly score higher than a child who spent his or her toddler years with a babysitter who plunked the kids down in front of the TV.

Borland's prediction proved correct. As in the past, more children in affluent areas took the test, and a higher percentage of them then passed it. In District 2, which includes many of Manhattan's wealthiest areas, 28.2 percent of the children who took the test scored in the 97th percentile, the theoretical cutoff for the citywide gifted program, compared to 4.7 percent for District 8 in the South Bronx. Falling between these extremes was District 30, which includes middle-income neighborhoods, such as Astoria and Sunnyside. There 12.2 percent of the test takers passed.

Earlier this month the Independent School Admissions Association of Greater New York, which represents many of the city's elite private schools, announced it would no longer require that the schools use an exam called the E.R.B. to help determine which 4- and 5-year-olds they'll accept. The group reportedly decided that widespread test prep had made the results all but meaningless. Of course, the applicants to kindergarten at the likes of Chapin and Dalton are playing on a level field: They all can afford test prep. When it comes to the public school gifted program, many applicants cannot.