The service sector in the U.S. saw a slowdown in November, an unexpected turn—especially given the usual health of holiday shopping, according to a recent article in Reuters. Most of the slowdown came from concerns related to trade tensions and worker shortage.

This off-kilter behavior appeared in The Institute for Supply Management's (ISM) index, with its reading falling about one point from roughly 55 to 54 from October to November. About two-thirds of the U.S.' economic activity fell above 50, which indicates expansion, including the service sector.

Economists from Reuters expected a dip in November, but they did not anticipate the drop off to be this drastic.

—Christie Citranglo, editorial associate