The University of Michigan's preliminary August consumer sentiment index reading was 80.0, compared to the final July 85.1, the preliminary July 83.9, and the final June 84.1, according to market sources.
The expectations index was 72.9, compared to the final July 76.5, the preliminary July 73.8, and the final June 77.8.
The current conditions index was 91.0, compared to the final July 98.6, the preliminary July 99.7, and the final June 93.8.
Economists polled by Thomson Reuters had predicted an 85.5 reading for the main index, 98.0 for current conditions and 76.0 for expectations.
The five-year inflation expectation index was 2.8%, compared to 2.8% in July, while the one-year inflation expectation index was 3.1%, compared to 3.1% in July.
The University of Michigan index is not released to the press, but only to paying subscribers.