Retail sales advanced by their biggest margin so far this year, advancing 2.9% on a year-over-year basis in the week ending Aug. 2, according to a weekly survey from the International Council of Shopping Centers (ICSC) and UBS Securities. Similarly, the Johnson Redbook retail survey recorded a 3.5% gain in the week compared to last year.

On a week-over-week basis, however, ICSC-UBS sales were flat, following a 1.2% advance in the previous week.

"Eleven states and the District of Columbia held sales tax holidays this week which helped to spur customer traffic for back-to-school items in those areas," said Michael Niemira, chief economist at ICSC.



"However, overall national traffic trends were softer which led to a flat weekly performance," he added, forecasting that July sales should advance by 2% or 3% overall.

The ICSC-UBS survey examines 75 retail chain stores in the U.S. excluding restaurants and vehicle demand.

Compared to June, July sales improved by 1.4%, according to the Redbook report, which measures 9,000 retail units.

By Patrick McGee and edited by Stephen Huebl