For the Chicago Public Schools, the empty seats undermine efforts to boost achievement and cost the district millions in attendance-based funding.
For children born into poverty, the flood of missed days threatens to swallow any hope for a better life.
The investigation is based on internal attendance data on about 247,000 elementary-level CPS students from 2010-11, the most recent year available. To assess the total number of missed classroom days per student, the Tribune analyzed both excused and unexcused absences, as well as gaps in enrollment.
Among the paper's findings:
• The crushing pattern of detachment from school often begins in kindergarten, when no child can be said to have a choice in the matter. In the 2010-11 school year, 19 percent of Chicago kindergartners were officially listed as chronic truants because they racked up nine or more unexcused absences.
• Absenteeism in the elementary grades is especially acute in African-American communities on the South and West sides. Counting truancy, excused absences and gaps in enrollment, more than 20 percent of black elementary school students missed at least four weeks of school in 2010-11, compared with 7 percent of whites and 8 percent of Hispanics.
• Children with a learning or emotional disability also miss class in disproportionate numbers, despite federal laws designed to keep such students in school. About 42 percent of K-8 students with an emotional disability missed four weeks of classes in 2010-11, compared with 12 percent of students without a disability.
• The district's official attendance statistics obscure the depth of the problem because officials are required to count a child as absent only if he or she is actively enrolled. The Tribune identified thousands of students who were out of school for four weeks or more because their families enrolled them late, pulled them out early or lost time while transferring between Chicago schools. But those missed days aren't counted as absences.
CPS spokeswoman Robyn Ziegler acknowledged that "there are far too many children who are missing more than four weeks of school in a given year, and that really eliminates any ability to establish a routine and a sense of belonging or for any degree of continuity in learning."
The cash-strapped school system could reap close to $9 million if it boosted attendance by just 1 percent, according to Tribune calculations confirmed by state education officials. Yet city officials have steadily choked off anti-truancy resources amid massive budget shortfalls and a frequent churning of top administrators.
"These are the kids who most need the help, and principals just don't have the resources," said Julious Lawson, principal of Von Humboldt Elementary on the Northwest Side. "We don't have truant officers. We don't ... hold parents accountable when their kids are not in school."