The U.S. economic index increased higher than anticipated in August, rising 0.9% and beating economists' projections of a 0.6% rise and following a 0.8% rise in July, according to The Conference Board.

The increase reflected positive contributions by eight out of 10 indicators, including the outlook for average weekly jobless claims that increased by 16,000 to 351,000.

"We expect claims to return to their downward path in the weeks ahead, but the data will be more uneven as claims get closer to pre-pandemic levels," said Nancy Vanden Houten, lead U.S. economist at Oxford Economics in New York.

The Coincident Economic Index increased by 0.2% to 150.9, following a 0.6% increase in July and a 0.5% increase in June. The Lagging Economic Index increased by 0.1% to 106.3, following a 0.5% increase in July and a 0.1% increase in June.

"The U.S. LEI rose sharply in August and remains on a rapidly rising trajectory," said Ataman Ozyildirim, senior director of economic research at The Conference Board. "While the Delta variant — alongside rising inflation fears — could create headwinds for labor markets and the consumer spending outlook in the near term, the trend in the LEI is consistent with robust economic growth in the remainder of the year.

"Real GDP growth for 2021 is expected to reach nearly 6 percent year over year, before easing to a still-robust 4 percent for 2022."