US Treasury Secretary Janet Yellen stated on Thursday that surprisingly strong economic growth in the fourth quarter was a "good thing" that indicates productivity gains and healthy spending without an increase in inflationary pressures.

Key quotes

"I see this as a good thing, reflective of strong, healthy spending and productivity improvements and not, most likely, creating an inflationary challenge.”
“Q4 GDP data driven by strong, healthy spending' and productivity improvements.”
"It may be that we're having a period of more rapid productivity growth than we've seen as a long-run average in recent years for the US.” 
"Some goods prices are falling and there is continued moderation in wage growth, which is important for controlling the prices of services."
"It is unclear if recent productivity gains are temporary, too soon to speculate on the impact of artificial intelligence on productivity."
"To me, more output is a good thing if it doesn't signal worrisome pressures in the labor market