A key measure of consumers' attitudes is slightly higher so far this month, but didn't rise as much as expected, according to preliminary data released Friday. The Index of Consumer Sentiment hit 90.4 in August, the University of Michigan said. Economists expected the consumer sentiment index to hit 91.5, versus 90 in July's final reading, according to a Thomson Reuters consensus estimate. The monthly survey of 500 consumers measures attitudes toward topics like personal finances, inflation, unemployment, government policies and interest rates - CNBC.