It didn't take long for Walter Mitchell, 16, to draw a connection between teenagers without jobs in Philadelphia and the recent looting and vandalism in Baltimore.
"If those kids would have been at work," they would not have been out on the streets, said Mitchell, of North Philadelphia, a high school student with ambitions to study mechanical engineering in college. "They wouldn't have risked losing their jobs.
Mitchell stopped to talk last week outside the Philadelphia School District's central administration building. Inside, he and other teenagers had formed a line nearly a block long as they waited to sign up for work permits.
Judging by the length of the line, there's no doubt teenagers, whether dropouts or enrolled in high school, want work.
But the jobs aren't there - they're being filled by older workers hanging on in the labor force, by college students who, despite the recovery, still can't get jobs in their fields, and by poorly educated foreign-born workers, including some who are undocumented.
Hardest hit are African American males ages 16 to 19, according to a new report by Drexel University, "Left Behind: Jobs Recovery Bypasses Philadelphia Teens."
Only one in 10 black male teenagers in Philadelphia has a job.
That statistic "should send shock waves through the community," said Paul Harrington, a labor economist at Drexel and co-author of the study.
Hispanic teens had the biggest drop in employment, with 20 percent working in the 2012-13 school term, down from 30 percent in 2006-07.
It might be easy to dismiss the ambitions of teenage workers, saying they just want to buy pizza and sneakers, but Harrington and other economists don't see it that way.
Because the young people aren't working, they aren't gaining the soft skills that will help them succeed at jobs later.
Harrington cites other research showing that teenagers who worked 20 hours a week as seniors in high school at the turn of the century were earning 20 percent more than their jobless counterparts six to nine years later.
"One of the pathways to mobility is early work experience -- just being in the culture of work," Harrington said.
Not only do individuals lose out, but the entire economic capacity of a community is affected as a rising generation of workers lacks the skills to be productive, Harrington said.
"The American dream is a full-time job," he said. "It's unhealthy for a community to feel mobility ladders are broken. 'I can't move up. I'm stuck. I'm a young man, but I can't act like men should act.' "
Summer jobs, studies show, lead to less violence, and not only because the teens are too busy working.
The summer-job effect, whether from mentoring or higher self-esteem, lingers even a year later, according to research by Sara Heller, an assistant professor of criminology at the University of Pennsylvania.
The issue resonates in the city.
In a recent mayoral forum on the workforce, each candidate touted the importance of work for teenagers and all pledged to use the office to coordinate efforts between schools and employers.
Philadelphia lags behind other cities in youth employment. In Fort Worth, Texas; Boston; and Denver, three in 10 teens had jobs in 2012-13, the most recent data available in Harrington's research. In Philadelphia, 15.8 percent had jobs, better than New York, Los Angeles, and Detroit, but below every other large city.
Harrington does not delve into whether teenagers want to work, which is what the unemployment rate measures. He simply compares those working with the entire population in that age group, a ratio used in U.S. Labor Department reports.
For the most part, nationally from the late 1940s through the dot.com bust at the turn of the century, from 40 percent to 50 percent of teenagers were working, Harrington's research showed.
But something changed around 2001. Jobs for teens plummeted, with 46 percent working in 2000 to a low of 25.5 percent in 2011. Even in the recovery, that number rose to only 28.7 percent at the end of March.
Employers, Harrington said, would rather hire older people with experience or college graduates, who have proved their reliability by going to class and getting their degrees.
"A 16-year-old kid is at the bottom of that queue," Harrington said.
In 2013, he and colleagues surveyed employers to track their attitudes about teen workers. They disagreed with the suggestion that teenagers were not interested in work - they had plenty of teenage applicants for entry-level jobs.
Employers were split on whether teens' reading, writing, and math skills were weaker, but all agreed their technology skills were stronger and they were easily trained.
The problems lie with absenteeism, lateness, and teens' inability to cover enough shifts, the report showed.
Outside the Philadelphia School District administration building, teenagers had no problem explaining why they wanted to work.
Santiago Orozco, 19, counts himself lucky that his parents, one who cleans houses and the other who works in construction, can take him along and get him a few hours of pay a week.
But it's not enough.
"Work gives you experience, responsibility, being in control of your life. It can affect you many ways - morally, the value you have of yourself," he said.
DaShawn Sealy, 17, of West Oak Lane, a junior at the Charter High School for Architecture and Design, had a job at Sesame Place last summer. This year, he wants to work closer to home.
"Work builds character," he said. "It gives you a taste of the real world."