The Great Recession was especially devastating for people between the ages of 16 to 30 who lack a high-school education. And the opportunities have not gotten much better for them despite a surge in hiring and a plunge in unemployment over the past several years.

A new study on minimum-wage increases shows that the percentage of these young people who held a job fell to 28% from 40% between 2006 and 2010. Although more people in that bracket have since found work, the study found, only 33% were employed at the end of 2014.

The study was conducted by economist Jeffrey Clemens of the University of California at San Diego, who has previously researched the effect of higher minimum wages. His latest work was published under the aegis of the National Bureau of Economic Research.

Also read:The facts on who earns the minimum wage

Clemens estimates that rising minimum wages reduced employment among 16- to 30-year-olds without a high school degree by 5.6 percentage points from 2006 to 2010.

Put another way, rising minimum wages accounted for almost half of the decline in the share of these workers holding a job during that five-year period.

Here’s some more bad news for millennials in that bracket. Not only are far fewer of them working, but their wages have essentially stagnated. So it’s even harder for them to make ends meet.

The new study is not the final word on the minimum wage, a subject of intense dispute in recent years as many states and even some cities push for sizable increases in what low-income workers must be paid.

Also read:Hillary Clinton calls for $12 minimum wage.

Some researchers such as Clemens believe higher minimum wages have been harmful. “The evidence supports the view that this period’s minimum wage increases had significant, negative effects on low-skilled workers’ employment,” he wrote in his latest study.

Yet other economists argue that rising minimum wages have little or no effect overall on employment. Higher pay for millions of low-income workers more than offsets the loss of relatively few jobs, they also contend.

Regardless of who’s right, it’s clear that less educated workers have suffered more from the Great Recession — and they continue to suffer.