BOSTON — The state’s retail stores are optimistic about the holiday shopping season that shifts into full gear later this week.

The Retailers Association of Massachusetts notes that consumer confidence remains high and this year’s calendar offers five full weekends between Thanksgiving and Christmas. There were only four last year, when brick and mortar stores reported a 1 percent drop in holiday sales from the previous year.

The group is forecasting a 3.1 percent increase in sales this holiday season, while cautioning that margins and profits could be tighter.

The overall U.S. forecast from the National Retail Federation projects increased sales of 3.6 to 4 percent.

Retail stores face ever-increasing competition from online shopping.

Retailers surveyed by the association expect seasonal store hiring to be comparable to a year ago.