Expect the unexpected.

Oct 14 (Reuters) — U.S. consumer sentiment unexpectedly slumped in early October as worries about declining incomes drove consumer expectations back down to the lowest level in more than 30 years, a survey released on Friday showed.

The Thomson Reuters/University of Michigan’s preliminary reading on the overall index on consumer sentiment sagged to 57.5 from 59.4 the month before. It fell short of the median forecast of 60.2 among economists polled by Reuters.

Consumers’ outlook also deteriorated with the gauge of consumer expectations falling to its lowest level since May 1980 at 47.0 from 49.4. The index had fallen to this level in early September before being revised up at the end of the month.