On Oct. 8, The Wall Street Journal published an article about a feud between the U.S. Chamber of Commerce and Apple, which had recently left the Chamber due to a disagreement over the group’s position on climate-change policy. About halfway through, the piece makes a passing mention to the Chamber’s membership (my emphasis):

Mr. Donohue said his group, which claims 300,000 members, supported efforts to fight climate change through federal investments and incentives to develop alternative forms of energy that can be produced without emitting carbon dioxide.

Six days later, the Chamber held a press conference to kick off its “Campaign for Free Enterprise,” a multi-million dollar effort to promote job growth and oppose what the group sees as unwarranted government intrusion into the private sector. Many news organizations covered the event, including the Associated Press, whose story concluded:

The U.S. Chamber of Commerce claims a membership of 3 million businesses and organizations.

Three hundred thousand vs. three million is quite a discrepancy. So which rendering is more accurate? According to Chamber spokesman Eric Wohlschlegel, it’s the Journal’s. Read the WSJ passage in an interview Friday morning, he said, “That’s accurate.” After hearing the AP’s, he responded, “That’s not exactly reported correctly.”

Those answers may have some bearing on a controversy that’s bubbled up in recent weeks, in the shadow of the story over a few high-profile departures from the group: Just how many members does the Chamber have, and how should news organizations describe its size?

The question has been pushed by Mother Jones staff reporter Josh Harkinson, who reported last week that while news accounts typically refer to the Chamber’s three million members, the organization’s roster of direct, dues-paying member businesses is about one-tenth that size. The larger number is derived from counting businesses that belong to state and local chambers, many of which belong to the national organization. But while the U.S. Chamber does claim to “represent” businesses that belong to the smaller chambers, those companies are not direct members of the national group.

The distinction matters, Harkinson argues, because the larger figure makes it appear that support for the Chamber’s positions—many of which Mother Jones opposes—is more broad-based than it really is. “The Chamber claims to speak for the U.S. business community,” he says, and the widespread use of the three million figure “certainly adds to” the impression that it does. But if many of those three million aren’t sustaining the Chamber financially or playing a role in setting its policies, how meaningful is the number? On Wednesday, Harkinson published an open letter to several reporters who had recently used the “three million” figure (sometimes with caveats or qualifiers), asking them to publish a correction.

On the issue of the size of the Chamber’s membership, there’s not actually much dispute. On Friday, Wohlschlegel said the organization has about 360,000 direct members (a number, he emphasized, that has been growing since executive director Tom Donohue took over); in addition, it counts about 1,200 state and local chambers and about 900 trade associations as members. And the Chamber does cite this figure publicly. A webcast of the October 14 “Free Enterprise” event shows its vice chairman, Thomas Bell, refer to the group’s “multifaceted membership, over 300,000 strong.” And according to this Chamber blog post, the Journal’s citation of the lower figure was based on Donohue’s remarks at a press conference the day before. (The WSJ reporter on the story did not reply to an e-mail seeking comment.)

On the other hand, the “three million” figure doesn’t appear in press accounts by chance. In the October 14 webcast, Donohue also refers to “the entire Chamber of Commerce federation—three million strong.” And the boilerplate that concludes the Chamber’s press releases reads as follows:

The U.S. Chamber is the world’s largest business federation representing more than 3 million businesses and organizations of every size, sector, and region.

The words “federation” and “representing” are key—the Chamber is careful not to claim three million members, and its language is not, strictly speaking, inconsistent (though Harkinson has noted at least one instance in which the Chamber did refer to having “over three million members). But for the “three million” figure to have meaning, that “representation” must have real value—and while the Chamber no doubt believes that it does, it’s not clear that the media should readily accept that claim.

Greg Marx is an associate editor at CJR. Follow him on Twitter @gregamarx.