Restraining Unit Labor Costs is a Right-Wing Conspiracy by Steve Randy Waldman

That all sounds reasonable. But Yglesias has fallen into a trap. Unit labor costs are not “basically wages divided [by] productivity”. That’s not the right definition at all. [See update.] Unit labor costs are nominal wages per unit of output. With a little bit of math [1], it’s easy to show that

UNIT_LABOR_COSTS = PRICE_LEVEL × LABOR_SHARE_OF_OUTPUT 

An increase in unit labor costs can mean one of two things. It can reflect an increase in the price level — inflation — or it can reflect an increase in labor’s share of output. The Federal Reserve is properly in the business of restraining the price level. It has no business whatsoever tilting the scales in the division of income between labor and capital.

Yet throughout the Great Moderation, increases in unit labor costs were the standard alarm bell cited by Fed policy makers as an event that would call for more restrictive policy. And all through the Great Moderation, except for a brief surge during the tech boom, labor’s share of output was in secular decline. (More recently, the Great Recession has been accompanied by a stunning collapse in labor share. Record corporate profits!)

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Update: It is easy to show that unit labor costs are not equal to total wages divided by labor productivity. But Nick Rowe points out in the comments that unit labor costs are equal to the average hourly wage divided by labor productivity. So, depending on how you want to interpret “wages”, I was too quick in tweaking Matt Yglesias for a misstatement. Sorry!