The article is interesting throughout but the excerpt below caught my eye.
It goes to the edge but does not explicitly mention the important concept of "Increasing Opportunity Costs" and the reason the Production Possibility Frontier (or Curve) is "bowed", or concave from the origin.
“The changing distribution of workers might be able to explain up to one-half of the slowdown in labor productivity growth from 2.5% to 1.5% per year since the 1960s," said Dietrich Vollrath, a University of Houston economist. Indeed, this effect has accelerated since 2000, when workers, in aggregate, started to move from higher to lower productivity sectors.
Services productivity, besides its natural disadvantage, may be facing an added headwind: The sector is absorbing millions of workers whose underlying skills may not be well suited to the jobs they take on.
If people start doing work they are relatively good at, and if manufacturers shed their least efficient workers first, manufacturing productivity will improve as it downsizes but services-sector productivity will suffer as it absorbs workers who are a poor fit. (Sections in bold are mine).