FORTUNE -- The two leading high tech market research firms have done it again.
They issued their preliminary PC sales estimates for the first calendar quarter of 2013 Wednesday, and while they agree that it represented either the worst quarterly decline on record (IDC) or the worst in a generation (Gartner) -- thanks in large part to the disruption caused by the iPad and its imitators -- they can't seem to get their stories straight on the sales of Apple's (AAPL) computers.
We've seen the two firms get their Mac signals crossed before, but never this badly. In the summer of 2012, IDC had U.S. Mac sales falling 1.1% in the second quarter while Gartner had them growing 4.3% -- a 5.4% gap. This time they disagree by nearly 15%.
You used to be able to explain these discrepancies by the fact that Gartner reported shipments to end users and IDC shipments into channel (i.e. distributors). But now they both claim their numbers include shipments to end users, so that explanation doesn't wash.
What all this really shows is that unless these celebrated firms are working from sales figures supplied by the companies themselves, they're giving us numbers that look solid and definitive but are more like data soufflés. Kick them a couple times and they're liable to collapse.
In the PC market, where the largest players report unit sales on a quarterly basis, things eventually shake out.
But in the increasingly important smartphone and tablet markets, in which Apple issues unit sales numbers but its largest competitors don't, Gartner and IDC -- and all the analysts who depend on them -- are flying blind.
Below the fold: the two firms' Q1 2013 spreadsheets, for what they're worth.
Piper Jaffray's Gene Munster says growth may not return until the back half of 2013
FORTUNE -- In February, Gene Munster predicted that Apple (AAPL) would get a boost this quarter from product announcements in March or April.
With March almost over and the quarter ending on Saturday, Piper Jaffray's senior Apple analyst issued a note to clients Tuesday warning that the company will have to get through a dry patch before MOREPhilip Elmer-DeWitt - Mar 26, 2013 6:43 AM ET
Ranking the best and worst Apple analysts for fiscal Q1 2013
FORTUNE (Koh Ngai, Thailand) -- As evidenced by Apple's (AAPL) sickening $55.5 (10.8%) drop in after-hour trading Wednesday, the analysts who cover the company -- both on and off Wall Street -- aren't doing it any favors.
The company didn't have a bad quarter. In fact, it posted its best quarter ever with earnings per share of $13.81 on sales of MOREPhilip Elmer-DeWitt - Jan 23, 2013 8:16 PM ET
The analysts' forecasts range from 4.45 million to 6.5 million. Median estimate: 5.2 million
FORTUNE (Vientiane, Laos) -- At first glance, the chart at right looks pretty dismal. It suggests that Wall Street expects Christmas quarter sales of the Mac to grow less year over year than any year in memory, and that our sample of independent analysts -- generally more bullish than the professionals -- expect year over year unit MOREPhilip Elmer-DeWitt - Jan 12, 2013 6:27 PM ET
Is this the machine on which Broadwell carried on her affair with General Petraeus?
FORTUNE -- Help me out here, Mac experts. The computer being hauled out of Paula Broadwell's home (with her permission) by FBI agents as part of their investigation of the Petraeus affair looks to me like an Apple (AAPL) iMac circa 2009. Can you confirm or deny?
Below: An annotated photo of the back of a 2009 iMac MOREPhilip Elmer-DeWitt - Nov 13, 2012 1:43 PM ET
Q: How do you convince a great American company to bring that manufacturing back?
FORTUNE -- Toward the end of the second presidential debate, moderator Candy Crowley asked Mitt Romney and Barack Obama about Apple (AAPL).
"iPad, the Macs, the iPhones, they are all manufactured in China," she began. "One of the major reasons is labor is so much cheaper [there]. How do you convince a great American company to bring that manufacturing back here?"
GOVERNOR MOREPhilip Elmer-DeWitt - Oct 17, 2012 5:28 AM ET
It's been falling ever since and is now approaching 1985's level
FORTUNE -- In a chart posted on Twitpic Monday, Asymco's Horace Dediu shows that the multiple of PCs sold to Apple (AAPL) Macs sold has been falling steadily since it peaked in 2004 and is approaching the ratio of 1985.
Brian S Hall points out in his Smartphone Wars blog that 1985 was the year Microsoft (MSFT) released Windows. "It was MOREPhilip Elmer-DeWitt - Jul 3, 2012 5:54 AM ET
Is Wall Street expecting AAPL to get a post-conference bounce? You be the judge.
FORTUNE -- Apple's (AAPL) World Wide Developers Conference -- its only remaining public event not explicitly linked to a product announcement -- is set to open in San Francisco Monday, and several analysts issued notes Friday telling their clients what to expect.
Merrill Lynch's Scott Craig: Clockwork-like software innovation is often overlooked. WWDC mainly serves to showcase the latest MOREPhilip Elmer-DeWitt - Jun 8, 2012 10:44 AM ET
What Tim Cook didn't say in last week's earnings call
FORTUNE -- When it reports on Mac sales in its retail stores, Apple (AAPL) likes to make the point -- as Tim Cook did again last week -- that roughly half of the Macs sold in Apple Stores are sold to customers who never owned a Mac before.
In a report issued Monday entitled "What Tim Cook Didn't Say," Consumer Intelligence Research Partners, MOREPhilip Elmer-DeWitt - Apr 30, 2012 2:58 PM ET
Having fallen nearly 13% since April 10, the stock popped 7.44% on the news
FORTUNE -- After losing more than $70 billion in market value in two weeks, Apple (AAPL) capped one of the strangest earnings walkups in memory by handily beating all but the most optimistic estimates, reporting record March quarter earnings of $12.30 per share on sales of $39.2 billion.
Shares reversed course as soon as the news broke, climbing more MOREPhilip Elmer-DeWitt - Apr 24, 2012 5:04 PM ET
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