Joblessness averaged 20.7% in France's poorest urban areas last year, double the national average, according to a survey of 200 cities and towns conducted for the employment and social cohesion ministry.
But the picture is even bleaker for the young - for those aged 15 to 25, the figure is 36% for males and 40% for females.
And despite a rally in national job figures this year, unemployment among the poor continues to worsen.
Experts say the areas hardest hit by almost two weeks of unrest, which has spread from the capital to cities throughout the country, exhibit similar characteristics - a lack of businesses, large numbers of unemployed with few qualifications or skills, and the issue of skin colour.
"Even those who have been through university find themselves unemployed or working in jobs below their qualifications," says Samuel Thomas, vice-president of SOS-Racisme.
"Even those who have been through university find themselves unemployed or working in jobs below their qualifications"
"When an accountant finds himself working as a shopkeeper it compounds the hopelessness of the young people coming up."
The Equality and Anti-Discrimination Authority, in its first month of operation in July, logged 400 complaints, half of them about job discrimination, said president Louis Schweitzer.
"The first source of discrimination is origin," said Schweitzer, a former chief executive of automaker Renault.
With television news programmes showing nightly images of flaming cars and ranks of riot police in helmets and shields, commentators have agonised over France's apparent failure to absorb millions of immigrants from its former colonies.
But Guillaume Merzi, of the Integration Council, insisted it would be going too far to say integration had failed entirely.
Experts say skin colour is still
used to discriminate people
"Several measures have been put in place, which will work over the medium- to long-term. They have to be pursued," he said.
The measures are mainly directed at trying to force a wedge through the country's notoriously inflexible labour system, including contracts that cut through red tape-cutting for youngsters to encourage employers to hire more young people.
Taxes and fees have been waived for companies setting up in deprived areas on the proviso that they hire at least one-third of their work forces locally.
Many would like to see a labour law requiring anonymous CVs, which would make it harder for employers to weed out job seekers on the basis of ethnic origin.
"It would allow each person to at least defend their application in an interview and to make recruiters aware of the absurdity of their prejudices," said SOS-Racisme.
The group has appealed to employment offices to alert legal authorities about employers who choose only "blue-white-red" candidates, those of purely French stock.
While anti-racism groups dismiss the diversity charters already drawn up by 200 French businesses as "decoys", some companies such as McDonald's have been credited with making progress in the fight against discrimination.
The head of the the French employers' federation, Laurence Parisot, has offered to negotiate with unions on the issue of employee diversity.