NEW YORK, United States — Americans’ confidence in the economy improved slightly in August, but the mood is still gloomy amid job worries, according to a monthly survey.

The Conference Board said yesterday that its Consumer Confidence Index now stands at 53.5, up from a revised 51.0 in July. Economists surveyed by Thomson Reuters had expected 50.5. The increase comes after two straight months of declines.

It takes a reading of 90 or more to indicate a healthy economy — a level not reached since the recession began in December 2007. The index — which measures how Americans feel about business conditions, the job market and the next six months — had been recovering fitfully since hitting an all-time low of 25.3 in February 2009. But August’s reading suggests that American confidence hasn’t improved from a year ago, a bad sign for the economy and for retailers, which have been grappling with a weak start to the back-to-school season.

Economists watch confidence closely because consumer spending accounts for about 70 per cent of US economic activity and is critical to a strong rebound. But worries are rising the economy is growing too slowly to support sustained job growth, and some are concerned it could fall back into a recession.