Retailers from Wal-Mart Stores to Gap, RadioShack and Walgreens are opening their doors on Thursday as U.S. families celebrate Thanksgiving, aiming to capture early bird shoppers a day before the official start of holiday shopping on Black Friday.

The unsettled state of the U.S. economy, with a 26-year high in unemployment and tighter access to credit, has industry holiday sales forecasts varying from a decline of 3 percent to an increase of 2 percent.

"The consumer is confused. They don't know whether to spend or not," said Marshal Cohen, senior analyst at retail consultancy NPD Group.

As the holidays draw closer and deeper discounts beckon, consumers may splurge a bit more. Industry experts expect a strong turnout on the Black Friday weekend, but caution it will not mean a bumper holiday season as shopping trails off in the weeks before Christmas.

"The recession last year was a shock to the consumer. This year they are already tired of it," Cohen said. "They might even reward themselves for being frugal for the whole year."

Retailers insist they will stand firm this year and not offer the profit-sapping discounts used to clear merchandise off shelves last year. Cohen estimates that markdowns won't dip below 50 percent off, compared with the multiple discounts of 75 percent and more last year.

While that should help protect margins, it could prove to be a major disappointment to customers.