Workers may be suffering from lower pay as a result of their employers spending millions of pounds to keep their pension schemes afloat.
A report by the Resolution Foundation says such employees are unfairly losing an average of £200 a year.
It said those most affected are younger workers, many of whom will never benefit from the defined benefit pension schemes being protected.
In 2016, UK firms spent roughly £24bn trying to plug their deficits, it said.
Among the companies ploughing millions of pounds into their pension schemes were BT, Shell, Tesco, Unilever and Royal Bank of Scotland.
The current deficit of all defined benefit schemes in the UK is currently thought to be about £500bn.
The report says older workers, and those already in retirement, have the most to gain when companies top up their pension funds.
Of the 11 million workers still in defined benefit schemes, less than 2% are under 30 and still contributing.
Half the 6,000 schemes in existence are closed to new members, with a further third closed to further contributions.