People carry shopping bags as they visit a department store during the holiday season in New York City.
Eduardo Munoz | Reuters
Retailers chalked up solid gains in the final month to wrap up the holiday season, according to the CNBC/NRF Retail Monitor for December.
However, the data also shows the true state of consumer spending is now clouded by a new factor: deflation.
The Retail Monitor, which excludes autos and gas, rose 0.4% in December, down from a gain of 0.8% in November, when the holiday shopping season traditionally kicks off. It’s just below the long-run average of 0.6%.
The core retail gauge, which also takes out restaurants, climbed a more…