Families with school-age children are expected to spend, on average, $563.49 on back-to-school merchandise this year, up 6.9 percent from last year's $527.08 average - and total back-to-school spending is expected to reach $18.4 billion, according to the National Retail Federation (NRF) 2007 Consumer Intentions and Actions Back-to-School Survey, conducted by BIGresearch.

Some data from the study, via MarketingCharts:

• The number of parents who plan to purchase merchandise online this year is expected to increase 40.8 percent, from 15.2 percent of parents last year to 21.4 percent this year.

• Sales in the electronics category will gain most this year, with families spending 13.0 percent more on electronics than last year ($129.24 vs. $114.38).
• Footwear will also undergo a higher-than-average sales increase, with sales expected to rise 10.3 percent over last year ($108.42 vs. $98.34).
• Families are also expected to spend $94.02 on school supplies, up from $86.22 a year ago.
• The majority of shoppers will be purchasing clothing and accessories this year (95.4 percent), and clothing and accessories remains the largest spending category at $7.6 billion.
• Clothing and accessories spending is expected to be flat, with consumers spending an average of $231.80 on those purchases, similar to last year's $228.14.

• The majority of consumers (45.2 percent) plan their shopping for three weeks to one month before school starts; 32 percent will begin one to two weeks before; 14.6 percent will begin at least two months before the start of school; and 5.4 percent will wait until the week before school begins. Only 2.7 percent will wait until after school starts to do their shopping.

MarketingCharts provides more data from the NRF study - as well as June retail sales figures.