New research shows Oregon's middle-class jobs are disappearing, while high-wage and low-wage jobs are growing.

The trend is known as job polarization. It has shaped the U.S. labor market for three decades, but the Great Recession exacerbated the process.

Polarization means work is gradually shifting away from the factory and office jobs that typically fall in the middle of the pay scale, with annual wages between $25,000 and $50,000.

A state study shows the vast majority of the jobs lost in Oregon during the recent recession were such middle class jobs.

Of the jobs recovered after the recession, more than half were occupations paying more than $50,000.  And most of the other half were jobs that pay less than $25,000.

Experts predict job polarization will continue for years to come.