“For more than a year, there has been a high-profile debate over what Apple should do with its enormous cash reserve, now amounting to $137 billion. The proposals have been curiously one-dimensional, with a nearly exclusive focus on how the reserves should be used to reward its shareholders. Almost entirely absent from the discussion has been whether those reserves should also be used to provide fairer compensation to the workers making its products abroad or selling its products here. This imbalance is part and parcel of a larger trend: the share of economic rewards going to workers is diminishing.”

It’s not an idea many Apple (AAPL) investors are going to want to hear, especially with the stock down more than 36% from last September’s highs. But as author Isaac Shapiro points out, long-term shareholders have nothing to complain about. Those who stuck with the company over the past five years have seen the value of their investments grow more than three-fold.

Less amply rewarded are the 30,000 Apple Store employees who make as little as $25,000 a year. Or the roughly 1 million Asian contract workers who take home, before overtime, between $225 and $288 per month.

Shapiro doesn’t diminish the work Apple has done to raise pay scales and improve working conditions in its Asian supply chain. Nor does he suggest that Apple’s competitors are doing better.

But he does point out that some of the pledges Apple made have not been fulfilled.

For example, in March 2012 Apple promised that workers assembling Apple’s devices in Foxconn’s factories would be compensated for hours they had worked in the past that had not been paid for, including pre- and post-shift meetings, time spent in mandatory trainings, and as many as 30 minutes of “unscheduled overtime” on any given day.

According to Shapiro, none of that back pay was ever issued, and it appears that none is forthcoming.

[UPDATE: Several readers questioned this section, so I followed up with the Fair Labor Association, under whose auspices the back pay issue was investigated. According to the FLA, the unscheduled overtime issue affected only one worker, and it turned out he hadn’t filled out his time card. On the other issues — mandatory training and pre- and post-shift meetings — the FLA determined that it was a problem. The remedy proposed was for Samsung to change its practices and pay its workers for the such time going forward. No back pay was issued.]

He’s got more examples, laid out fairly dispassionately, in $45+ billion for Apple shareholders, nothing yet for Apple workers.

As I say, it’s probably the last thing Apple investors want to hear on yet another down day for the stock, but it does put those demands for bigger dividends and multibillion dollar stock buybacks in some perspective.