Analysts are questioning the latest retail sales figures

So much for a merry Christmas. That is, if you trust the numbers.

Figures released Thursday by the Commerce Department show U.S. retail sales fell 1.2 percent in December from the previous month in the biggest drop since 2009, rather than the slight increase economists had been expecting. Even more confusing: There was a pullback in a measure based largely on internet sales, which had been expected to be the U.S. retailing industry's saving grace this holiday season.

Some analysts reacted to the data not just with surprise but with an unusually large dose of skepticism. Jim O'Sullivan of High Frequency Economics said the figures were so much weaker than expected "that the data lose credibility," while Stephen Stanley of Amherst Pierpont Securities said the report "seems seriously out of whack" given mostly upbeat comments from retailers about the Christmas season.

The report was delayed about a month due to the partial federal closure, and "I'm actually wondering whether the government shutdown created issues for them in terms of data collection and quality," said Neil Dutta, head of economics at Renaissance Macro Research.

The Commerce Department's Census Bureau said in Thursday's report that while data collection was delayed by the shutdown, "processing and data quality were monitored throughout and response rates were at or above normal levels for this release." The bureau didn't immediately reply to a request for comment on the numbers.

The report showed non-store retailers -- which includes online stores -- fell 3.9 percent month on month in December, the most since November 2008. They rose just 3.1 percent on an unadjusted year-over-year basis, even as Amazon.com Inc. alone saw its net sales in North America grow about 18 percent in the fourth quarter.

Craig Johnson, president of retailer research firm Customer Growth Partners, said those figures for internet shopping seem particularly low, suggesting a possible undercounting of online transactions.

"There seems to be a significant undercount problem in the internet sales,'' Johnson said in a phone interview. "This is a real head fake."

Ward McCarthy, chief financial economist at Jefferies LLC, also flagged the strange online shopping data.

"Taken literally, this data release would indicate that the consumer sector collapsed in December," he said in an emailed note. "This release is such an outlier and so incongruous with the general trend in consumer spending, holiday consumer sales reports and holiday seasons consumer credit data that it does raise suspicions of data reliability."

In general, the disappointing holiday-period spending doesn't bode well for the next round of apparel and department-store results, scheduled for release in coming weeks. Walmart, the world's biggest retailer, reports its fourth-quarter results next week. Macy's, Best Buy and Nordstrom will also report before the end of the month. Macy's Chief Executive Officer Jeff Gennette already warned in January that sales "weakened in the mid-December period and did not return to expected patterns until the week of Christmas."

Not only was the report on December spending disappointing, but it also came much later than normal. Wall Street usually gets numbers on year-end spending by mid-January, but the partial federal-government shutdown meant those results were postponed by nearly a month.