ll the effort by Hawaii’s officials to boost the value of a public school education — pushing for more highly qualified teachers, more consistency and rigor in curriculum and standards — is sadly diminished by a growing problem with absenteeism. The best possible teachers in the classroom can’t reach the students whose seats are empty, day after day.

The state Department of Education has stepped up its surveillance of students, flagging them before they fall hopelessly far behind. And backed by support from parents and the larger community, educators must intercede early when problems arise and search for approaches that can bring chronically absent students back to the fold.

The scholarly record is packed with study after study showing the devastating effects of absenteeism, which frequently ends with students dropping out of school altogether. Dropping out of high school leads to poor outcomes in the life of a teen. U.S. Department of Commerce figures from 2009 show that adults, ages 18-67, who had not completed high school had a median annual income of $25,000, compared to $43,000 for those who had at least a high school credential.

Unemployment skyrockets for those who lack a diploma, and they also end up in prison more often. A 2007 report by researchers Henry Levin and Clive Belfield estimated that the average high school dropout costs the economy about $240,000 over his or her lifetime in lower tax payments, higher reliance on government programs and greater likelihood to commit crimes.

This problem has real costs, human and economic, which is why it’s distressing to see so many Hawaii students heading in that direction. The department recently released its first set of absentee figures for a full school year.

Dissected in a story by Star-Advertiser writer Mary Vorsino, the numbers are startling. At 26 high schools or multilevel schools with high school grades, one-fifth or more of the students were chronically absent, meaning they have missed 15 or more days. And 51 elementary schools mirror that 20 percent absentee rate.

At individual schools the picture is far bleaker. Waianae High is grappling with the most shocking conditions statewide: 815 students, or 48 percent of the school’s population, missed at least 15 days of the 180-day 2011 school year. Fifteen days is three full weeks. Picture how easy it is to fall behind in a math or science class, or in group projects, in that amount of time and it’s easy to see how students start to write themselves off as academic failures.

The DOE, with the prompt of the federal Race to the Top educational reforms, has greatly improved its tracking system, enabling faculty and administrators to flag students when a pattern of truancy starts to take shape. Further, moves to overhaul the federal No Child Left Behind law are hardening the mandate on schools to manage this problem.

This can be tough. Within each student’s family, myriad issues — illness, homelessness, unemployment, family discord — sap the parents’ resolve to handle their child’s truancy. Nonetheless, parents are the most responsible for seeing that their children are getting their education, and are duty-bound to respond to the first intervention by the school.

Ultimately, some students simply will struggle in vain to find their place within the conventional classroom setting, underscoring the need for alternative strategies. Threatened by fiscal shortfalls in recent years, programs such as alternative schools should get a high priority when budgets are set. And ensuring that the state provides enough avenues for students to earn their diploma and beyond, through continuing education and remedial tracks at community colleges, remains a key element of state educational policy.

These programs carry a high price tag, but the costs of doing nothing — a growing number of young adults ill-equipped to join society in any productive way — are sure to be much, much higher.