At 53.9 in December, the seasonally adjusted Markit final U.S. Services Business Activity Index dropped from 54.6 in November to signal the slowest upturn in service sector activity for three months. Nonetheless, the latest reading was well above the neutral 50.0 threshold and pointed to a solid pace of expansion. Moreover, the average reading during the final quarter of 2016 (54.4) was the strongest since Q4 2015.