Despite the economic slump, back-to-school spending is expected to climb this year as families cash in their federal tax rebate checks to buy electronics, clothing and school supplies, according to the National Retail Federation.

In a survey of more than 8,000 consumers, about a fifth said they planned to put aside part of their tax rebate checks for back-to-school shopping, the Washington D.C.-based trade group said. The average U.S. family is expected to spend $594 on school-related purchases in the months ahead, up from $563 last year, giving a $20-billion jolt to the economy.

Electronics will get the biggest boost, with average spending rising to $150 from $129 last year, the survey found. By contrast, spending on clothing, shoes and school supplies is expected to remain flat.

Most families are planning to shop at discount and department stores this year, while a growing number are going online.

A recent survey by Marketing to Moms Coalition also forecasts stronger spending.

Meanwhile, back-to-college spending is expected to drop seven percent this year, to an average of $600 per student, the trade group reported.