"Through both economic boom and bust during the past two decades, our job satisfaction numbers have shown a consistent downward trend," said Lynn Franco, director of the Consumer Research Center of The Conference Board, in a prepared statement.
"[That] could spell trouble for the overall engagement of U.S. employees and ultimately employee productivity," she added.
The report notes that job satisfaction has steadily declined over the years despite big improvements in the work environment, such as a reduction of workplace hazards and an increase in vacation days.
The drop in satisfaction over the past 22 years spans various aspects of employee life, including interest in work (down 18.9 percentage points) and job security (down 17.5 percentage points).
And employee satisfaction dipped across the board; workers in every age group and income levels showed a drop, but workers younger than 25 were the most unhappy in their jobs.
Almost one-quarter of respondents said they didn't expect to be at their current jobs within a year.
Experts fear that U.S. is entering decade of job doldrumsJob Growth