After a slight increase August, the index declined from 81.8 to 79.9 in September, the research firm said.
The Present Situation Index rose from 70.9 to 73.2, but the Expectations Index, which measures confidence in the economy six months down the road, edged lower, dropping from 89 in August to 84.1 in September.
The indexes use 1985 as a starting point for comparisons. The averages for that year were assigned values of 100.
In the September survey that involved more than 5,000 households, the percent of respondents who indicated they believe business conditions were "good" rose from 18.7 percent to 19.5 percent, while those indicating a belief that business conditions were "bad" fell from 24.5 percent to 23.9 percent.
The percentage of respondents indicating jobs were "plentiful," rose from 11.3 percent to 11.5 percent while those indicating jobs were difficult to get declined from 33.3 percent to 32.7 percent, a five-year low.
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