With Tennessee providing a 3-day exemption on sales taxes charged on more than 150 back-to-school items starting Friday, Chattanooga's biggest shopping mall is extending hours this weekend to help more consumers take advantage of the tax-free savings.

Hamilton Place mall will be open Friday and Saturday from 10 a.m. to 10 p.m. and on Sunday from noon to 7 p.m. Northgate Mall plans to keep its regular hours this weekend, however.

"We expect that it will be a very busy at both properties," said Stacey Keating, a spokesman for CBL Properties which owns and operate both of Chattanooga's malls.

Tennessee retailers will not collect the usual combined 9.25 percent sales tax on more than 150 different items during the 13th annual sales tax holiday, which starts Friday and continues through Sunday.

State and local taxes will not be collected on clothing, school and school art supplies that cost $100 or less per item and computers that cost $1,500 or less.

Although targeted to help families cut the cost of preparing their children to go back to the classroom next month with the restart of school, the Department of Revenue said the weekend of savings is not exclusive to students or Tennesseans. Anyone who wants to shop in Tennessee during the last weekend of July is eligible to save on sales tax.

"The sales tax holiday provides savings for families preparing to send their children back to school and we encourage all Tennesseans to take advantage of this tax break on the necessary clothing and supplies before the start of the new school year," Gov. Bill Haslam said in a statement.

NFIB State Director Jim Brown says this weekend's sales-tax holiday on clothes, school supplies, and computers will be a shot in the arm for many small businesses.

"When you combine the sales-tax holiday with the usual back-to-school deals, you really put people in the mood to shop," Brown said. "Even if you don't need school clothes, you can save a lot of money by shopping during the sales-tax holiday. The sales-tax holiday can really help you stretch a dollar."

NFIB is asking shoppers to buy at least some of their school clothes and supplies at small, locally-owned businesses, Brown said.

"You can find some great deals and unique merchandise when you shop small," he said. "Plus, you support local retailers, you support the businesses that support local charities and schools and create jobs."

Retailers selling school supplies are expecting a big sales weekend.

"We've fully stocked the shelves for the entire back-to-school shopping season with a wide selection of products that include our best-selling items such as pencils, pens, USB drives, backpacks and copy paper," said Joni Fletcher, a spokesman for Office Depot.

The tax-free weekend may give a boost to merchants this weekend, but studies indicate that such gains are offset by lower sales later when such tax holidays end. That's why Georgia eliminated its sales tax holiday for back-to-school sales three years ago.

"While sales tax holidays are politically popular and they sound really great, they likely do not achieve the stated goals of saving money for parents of school-age children," said LeAnn Luna, a University of Tennessee business professor who has studied the impact of the sale tax holiday on activity. "Research has shown that there is no big impact on the local economy, because consumers simply shift their purchases into the tax holiday period."

While there is only a modest increase in store revenues, the tax holiday also create some administrative hassles, she said.

"Defining the exemption can be difficult," Dr. Luna said. "For example, do leg warmers, sweatbands, and bandanas qualify as clothing or accessories? There are also administrative costs to programming registers and computers to account for the holiday only to revert back to the original program after a day or a week. In some cases, businesses have to hire extra employees to work during this high-volume sales period."