(AP) — An improving economy and tax changes should help retail sales increase 3.8 percent to 4.4 percent this year, an industry trade group said Thursday.

The National Retail Federation’s forecast for 2018 comes after retailers saw the biggest sales increase since 2010 over the recent holiday period.

Low unemployment that means more competition for workers, as well as the tax changes, have led several companies to offer bonuses or raise wages. Retailers like Walmart, Best Buy and Lowe’s have done that so far, and more details about how retailers will use their tax savings may come as they report fourth-quarter results.

Jack Kleinhenz, the NRF’s chief economist, said shoppers will increase their spending as they start feeling that the tax cuts are permanent. “It will take some time,” Kleinhenz said.

Online and other non-store sales, which are included in the overall sales forecast, are expected to increase between 10 and 12 percent.

The numbers exclude automobiles, gasoline stations and restaurants.

Retail sales grew 3.9 percent to $3.53 trillion in 2017 from the previous year, according to the U.S. Census bureau’s preliminary estimate. The number may still be revised but exceeded the group’s forecast for growth of 3.2 to 3.8 percent. The retail industry enjoyed a better-than-expected 5.5 percent increase for November and December alone.