Adding up the entire retirement account balances of more than 116 million American workers amounts to just 41 percent of the savings accumulated by 100 U.S. chief executives, a study released Wednesday showed. The Center for Effective Government and Institute for Policy Studies found the 100 largest CEO retirement funds are, on average, worth $49.3 million per executive, or a combined $4.9 billion, Bloomberg News reported.

Pay and income inequality in the U.S. re-emerged recently as a pressing societal concern as the nation recovered from the deepest economic downturn since the Great Depression. But less attention has been paid to the growing gap in retirement savings between executives and workers, which the study’s authors are trying to address.

“This CEO-to-worker retirement gap is a lot bigger than the pay gap and one more indicator of the extreme level of inequality that is really tearing the country apart,” said Sarah Anderson, co-author of the report and global economy project director at the Institute for Policy Studies. Some of the studied chief executives with the largest retirement savings packages are at companies that recently cut retirement benefits for newer employees.

Researchers contrasted the difference between the retirement savings for executives and workers at various companies. For example, at Yum! Brands Inc., which owns the fast food chains KFC and Pizza Hut,  employees with a 401(k) have an average balance of $70,167, the report said. David Novak, who recently left as chief executive officer of Yum, is at the top of the executive retirement savings list, with $234.2 million. That’s about 3,300 times higher than the average employee, researchers said.

Many chief executives receive the bulk of their pay from deferred compensation plans, which permit executives to set aside salaries and bonuses on a pretax basis, often without limits, Bloomberg reported. But lower-paid employees with 401(k) accounts can only set aside $18,000 per year.