The data from the state Department of Revenue shows retail sales in January of $3.7 billion. That's nearly 5.4 percent higher than the same time last year -- and more than 16 percent above two years ago. Economist Dennis Hoffman of Arizona State University called that a nice solid month of performance. But Hoffman said there is reason to believe that this year-over-year growth may not continue.
"The headwind right now is $4 gas," said Hoffman. "And that is really going to be the proof in the pudding here."