An employee stacks produce in a Wal-Mart in Miami.  Wal-Mart announced earlier this year that it will raise the wages of its store employees to $10 per hour by next February. But activists say retailers should be moving faster to hike worker pay.  (Joe Raedle/Getty Images)

Retail workers — sales clerks, cashiers and stock people — account for one in six jobs in the United States and a large share of the new positions created in the years since the recession. Many of the jobs are low-paying, making retail a major culprit in one of the most difficult challenges confronting the economy: stagnant wages.

The situation is even more challenging for black and Latino retail workers, according to a report released Tuesday by the NAACP in conjunction with Demos, a public policy organization. Not only are they more likely than whites or Asians to work in retail, but they also tend to have the worst jobs in the retail industry, the report said.

Retail is the second-largest source of jobs for black workers in the country and has helped contribute to a recent reduction in the black jobless rate, which in April was 9.6 percent -- down from 11.4 percent a year earlier. But that is not all good, the report said. Retail work too often comes with some of the worst problems of the modern workforce: erratic schedules, involuntary part-time hours and low pay. Overall, the report said, 17 percent of black retail workers and 13 percent of their Latino counterparts are in poverty, compared with 9 percent of the overall retail workforce

Part of the reason is that black and Latino workers are less likely than whites and Asian retail workers to be supervisors and managers, and they are most likely to occupy the lowest-paying jobs, such as cashiers. In all, even when they work full-time, blacks and Latinos in retail make just 75 cents for every dollar earned by whites in the industry, the report said. Some 70 percent of black and Latino retail workers earn less than $15 an hour, compared with 58 percent of whites.

Blacks and Latinos are also more likely to be working part-time even when they would prefer full-time work in the industry.

The situation is gaining more attention as retail and other low-wage workers press for better pay and more predicable hours. Earlier this year, Wal-Mart,  the nation's largest private-sector employer, gave its lowest-paid workers a raise. Many analysts saw it as a reaction to a tightening job market, while others saw it as a response to growing activism to lift the pay of the nation's army of low-wage workers.

Wal-Mart said a half-million of its workers would be boosted to at least $9 an hour -- $1.75 above the federal minimum wage. By next year, their pay will go to at least $10 an hour. The company said workers will also have greater control over their schedules and would be given more opportunity for promotion and other career advancement.

Demos and the NAACP said that should only be a beginning. The advocacy groups want to see employers stop using credit checks to screen job applicants, a device they say has nothing to do with the reliability or productivity of potential workers. The credit checks only hurt the job prospects of people who have tougher work histories and more economic challenges, which work against blacks and Hispanics. They also want to see workers' pay raised to a minimum of  $15 an hour.

"Raising pay for workers at the bottom of the income distribution will improve living standards for for black and Latino workers employed in low-wage jobs, and reduce the racial wage gap," the report said.

Read more:

With victory in L.A., the $15 minimum wage fight goes national

Video: What every new Wal-Mart employee hears about why unions are terrible

Fired McDonald’s workers say they were dismissed for being minorities