An 11% surge in children's wear sales is expected to lead broad-based year-on-year gains across the apparel sector as a whole during the autumn shopping season, according to a forecast produced by software giant IBM.

The findings have substantial ramifications for retailers preparing for one of their most important seasons of the year.

The forecast relies on historical data and sophisticated analytics software developed by IBM to analyse both long-term trends and seasonal peaks, and is designed to help retailers and manufacturers improve performance by addressing complex supply and demand issues.

The children's apparel category stands out during the three-months from August to October, IBM says. It is expected to total $2.659bn - a rise of 11.1% over the prior-year period.

Women's apparel (+3.1%), men's apparel (+5.5%) and footwear (+3.2%) are all expected to post increases over the same period last year too - to $9.21bn, $1.93bn and $7.07bn respectively.

The forecast also indicates that for men's apparel, September sales will be up 10.5% over the 20-year average. For women's apparel, September sales will be up 2.15% over the 20-year average.

"This indicates that consumers are rotating between categories," says IBM retail analytics leader Michael Haydock.

"Adults are holding back on purchasing for themselves during their back-to-school shopping for the kids. But once the kids are in school, moms and dads will be looking to treat themselves. This category rotation, which became prominent after the economic downturn began in 2008, seems to be persisting."

Haydock also noted that disposable income, as reported by the US Commerce Department, continues to be healthy this year, perhaps indicating pent-up consumer demand.