JACKSON, Miss. - When it comes to high school graduation rates, Mississippi keeps two sets of books.
One team of statisticians working at the state education headquarters here recently calculated the official graduation rate at a respectable 87 percent, which Mississippi reported to Washington. But in another office piled with computer printouts, a second team of number crunchers came up with a different rate: a more sobering 63 percent.
The state schools superintendent, Hank Bounds, says the lower rate is more accurate and uses it in a campaign to combat a dropout crisis.
"We were losing about 13,000 dropouts a year, but publishing reports that said we had graduation rate percentages in the mid-80s," Mr. Bounds said. "Mathematically, that just doesn't work out."
Like Mississippi, many states use an inflated graduation rate for federal reporting requirements under the No Child Left Behind law and a different one at home. As a result, researchers say, federal figures obscure a dropout epidemic so severe that only about 70 percent of the one million American students who start ninth grade each year graduate four years later.
California, for example, sends to Washington an official graduation rate of 83 percent but reports an estimated 67 percent on a state Web site. Delaware reported 84 percent to the federal government but publicized four lower rates at home.
The multiple rates have many causes. Some states have long obscured their real numbers to avoid embarrassment. Others have only recently developed data-tracking systems that allow them to follow dropouts accurately.
The No Child law is also at fault. The law set ambitious goals, enforced through sanctions, to make every student proficient in math and reading. But it established no national school completion goals.
"I liken N.C.L.B. to a mile race," said Bob Wise, a former West Virginia governor who is president of the Alliance for Excellent Education, a group that seeks to improve schools. "Under N.C.L.B., students are tested rigorously every tenth of a mile. But nobody keeps track as to whether they cross the finish line."
Furthermore, although the law requires schools to make only minimal annual improvements in their rates, reporting lower rates to Washington could nevertheless cause more high schools to be labeled failing - a disincentive for accurate reporting. With Congressional efforts to rewrite the law stalled, Secretary of Education Margaret Spellings has begun using her executive powers to correct the weaknesses in it. Ms. Spellings's efforts started Tuesday with a measure aimed at focusing resources on the nation's worst schools. Graduation rates are also on her agenda.
In an interview, Ms. Spellings said she might require states to calculate their graduation rate according to one federal formula.
"I'm considering settling this once and for all," she said, "by defining a single federal graduation rate and requesting states to report it that way. That would finally put this issue to rest."
In 2001, the year the law was drafted, one of the first of a string of revisionist studies argued that the nation's schools were losing more students than previously thought.
Jay P. Greene, a researcher at the Manhattan Institute, a conservative research organization, compared eighth-grade enrollments with the number of diplomas bestowed five years later to estimate that the nation's graduation rate was 71 percent. Federal statistics had put the figure 15 points higher.
Still, Congress did not make dropouts a central focus of the law. And when states negotiated their plans to carry it out, the Bush administration allowed them to use dozens of different ways to report graduation rates.
As an example, New Mexico defined its rate as the percentage of enrolled 12th graders who received a diploma. That method grossly undercounts dropouts by ignoring all students who leave before the 12th grade.
The law also allowed states to establish their own goals for improving graduation rates. Many set them low. Nevada, for instance, pledged to get just 50 percent of its students to graduate on time. And since the law required no annual measures of progress, California proposed that even a one-tenth of 1 percent annual improvement in its graduation rate should suffice.
Daniel J. Losen, who has studied dropout reporting for the Civil Rights Project at the University of California, Los Angeles, said he once pointed out to a state official that, at that pace, it would take California 500 years to meet its graduation goal.
"In California, we're patient," Mr. Losen recalled the official saying.
Most troublesome to some experts was the way the No Child law's mandate to bring students to proficiency on tests, coupled with its lack of a requirement that they graduate, created a perverse incentive to push students to drop out. If low-achieving students leave school early, a school's performance can rise.
No study has documented that the law has produced such an effect nationwide. Experts say they believe many low-scoring students are prodded to leave school, often by school officials urging them to seek an equivalency certificate known as a General Educational Development diploma.
"They get them out so they don't have them taking those tests," said Wanda Holly-Stirewalt, director of a program in Jackson, Miss., that helps dropouts earn a G.E.D. "We've heard that a lot. It happens all over the system."
After several research groups questioned graduation rates, the federal Department of Education in 2005 published an estimated rate for each state, to identify those that were reporting least accurately. The figures suggested that nine states had overstated their graduation rates by 10 to 22 percentage points.
Part of the discrepancy is because many states inflate their official rate by counting dropouts who later earn a G.E.D. as graduates or by removing them from calculations altogether.
The undercounting of dropouts can be striking.
In Mississippi, the official formula put the graduation rate for the state's largest district, Jackson Public Schools, at 81 percent. Mr. Bounds, the state schools superintendent, said the true rate was 56 percent.
At Murrah High School, one of eight here, the official graduation rate is 99 percent, even though yearbooks show that half of Murrah's freshmen disappear before becoming seniors. Even Murrah's principal, Roy Brookshire, expressed surprise.
"I can't explain how they figured that, truly I can't," Mr. Brookshire said.
Governors also stepped in, worried that schools were not preparing the work force their states need. In December 2005, all 50 agreed to standardize their graduation rate calculations, basing them on tracking individual students through high school.
Fifteen states have begun to use the formula, said Dane Linn, director of the education division at the National Governors Association. And it has produced some stunning revelations.
In North Carolina, the rate plummeted a year ago to 68 percent from 95 percent. The News & Observer in Raleigh likened the experience to the shock of hearing a doctor diagnose a terrible illness.
"But now doctors can start treatments that can lead to a cure," the paper said in an editorial.
Mississippi is among the states that have become the most serious about confronting their dropout problem, Mr. Linn said.
The state has been building a record system capable of tracking student data from year to year, and in 2005 used it to estimate a graduation rate of 61 percent, 24 points below the official rate.
Mr. Bounds took office that fall and was initially consumed with the aftermath of Hurricane Katrina. But he eventually had time to pore over the data.
"It was time to boldly confront the facts," he said.
Mr. Bounds has used the new figures to persuade the Mississippi Board of Education to require school districts to prepare dropout prevention plans. Last month he told 2,000 community leaders that the state's dropout crisis was like "a Katrina hitting our schools every year."
The state will eventually report the lower rate to Washington but has set no schedule, Mr. Bounds said. One problem, he said, is that when Mississippi sends revised rates for its more than 200 high schools, their success levels will appear to plummet and many schools could be exposed to sanctions.
"It'll look like everybody has dropped, when actually everybody's doing a better job," Mr. Bounds said. "But we're capturing the right score on the scoreboard."
© 2008 The New York Times