WASHINGTON (MarketWatch) -- In its fight against inflation, the Federal Reserve has been chasing a phantom.

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Compensation pressures, which were thought to be exploding earlier this year, actually have been rather tame, recent revisions to wage and salary data show.

The impact of the revisions on inflationary pressures will be spotlighted Tuesday at 8:30 a.m. Eastern time, when the Labor Department will revise its estimates of third-quarter productivity. The report will be the highlight of a very light week for economic data. See Economic Calendar.

Productivity -- output per hour worked -- is expected to be revised higher to 4.5% annualized in the third quarter from 4.1% estimated a month ago, according to a survey of economists conducted by MarketWatch.

It would be the highest productivity gain in more than a year. After seeing the number of hours worked actually decline in November, economists are saying the fourth quarter should continue the above-trend growth in productivity.

Meanwhile, unit labor costs -- a key measurement of wage pressures on prices -- are expected to be revised lower to show a 1% annualized decline in the third quarter, rather than the 0.5% drop originally estimated.

But the shocker will come in with the revisions to second-quarter unit labor costs, according to Brian Jones, economist for Citigroup.

Instead of a 1.8% increase in unit labor costs in the second quarter, the revisions should show a 1.3% decline.

That means that unit labor costs, thought to be rising at a dangerous 4.1% year-over-year clip through the first half of the year, are really rising about 2%.