A new study on CEO compensation may reveal more about the U.S. economy than just growing pay disparity.

The leaders of the country's 350 largest public companies earned 312 times more than their typical employee in 2017. On average, CEOs made $18.9 million, a 17.6 percent increase from a year before, while workers' salaries remained mostly flat, according to a report by the nonpartisan Economic Policy Institute released Thursday.

The statistics are significant because these levels of pay disparity have only been seen before periods of economic slumps, including the dot-com bubble at the turn of the century and in 2007, a year before the recession, when the CEO-to-worker compensation ratio was 327 to 1.

"Average CEO compensation attained its peak in 2000, at the height of the late 1990s stock bubble, at $21 million (in 2017 dollars)--344 times the pay of the typical worker," authors Lawrence Mishel and Jessica Schieder write in the report. The CEO-to-worker pay ratio dropped to 188-to-1 in 2009 in the wake of the financial crisis, before steadily rising to the current level.

Other analysts and members of the business community have previously warned about an upcoming economic crisis. Last March during a Reddit AMA, for example, Microsoft founder Bill Gates said it was a "certainty" that the U.S. would experience another serious financial downturn at some point in the near future.