The Obama campaign today launched a new ad and website attacking Mitt Romney’s record as a “job destroyer” while he ran the private equity firm Bain Capital.

The Romney campaign responded that “Mitt Romney helped create more jobs in his private sector experience and more jobs as Governor of Massachusetts than President Obama has for the entire nation.”

Romney’s jobs claims deserve serious scrutiny. According to the Associated Press, Massachusetts added 24,400 net jobs while Romney was governor. The state ranked forty-seventh out of fifty in job growth during that time.

The number of jobs Romney presided over at Bain has varied widely according to his own estimates. When he ran against Ted Kennedy in 1994, Romney said he created 10,000 jobs while at Bain. During the 2012 presidential campaign, Romney’s campaign has claimed he created “over 100,000 new jobs,” “tens of thousands jobs” and “thousands of jobs” at Bain. It’s impossible to know if any of these figures are accurate—every time the Romney campaign is pressed on the details, the number of jobs he created at Bain seems to decrease.

“If he is to continue to make claims about job creation, the Romney campaign needs to provide a real accounting of how many jobs were gained or lost through Bain Capital investments while the firm managed these companies—and while Romney was chief executive,” wrote Washington Post fact-checker Glenn Kessler. “Any jobs counted after either of those data points simply do not pass the laugh test.” He gave Romney’s “over 100,000 new jobs” created “three Pinocchio’s,” which represents a “significant factual error and/or obvious contradictions.” In another analysis, Kessler wrote that “[Romney’s] campaign offered no definitive proof that Bain added more jobs than it eliminated while Romney headed the firm.”

Indeed, the jobs Romney supposedly created at Bain came from the growth of three companies Bain helped start—Staples, Sports Authority and Domino’s. But we have no idea how many jobs were lost at companies like GST Steel, which the Obama campaign spotlighted today, that went bust under Bain. Romney is only counting gross, not net, jobs created, which is not how jobs are calculated in the real economy. “It is utterly ridiculous for Romney to cherry-pick three companies where jobs were gained and ignore other companies where there were job losses while he was at Bain,” says Michael Linden, director for tax and budget policy at the Center for American Progress. “If you applied that same standard to Obama, you would have millions—if not tens of millions—of new jobs created during Obama’s term.”

Romney’s criticism of Obama’s jobs record is lacking crucial context. The country lost 4.2 million private sector jobs during Obama’s first term as a result of the economic crisis the president inherited. Since early 2010, the economy has added 4.25 million private sector jobs, resulting in a net gain of private sector jobs for the first time during the Obama administration. (The public sector has lost 607,000 jobs since Obama took office.)

These figures don’t mean that Obama has an ideal record when it comes to jobs. He should’ve been more focused on creating jobs and less concerned with reducing the deficit for the entirety of his administration and could be doing much more to stem the loss of public sector jobs. But Romney’s jobs record, to the extent that we even know what it is, is hard to take seriously, no matter what the candidate says. It’s impossible and misleading for Romney to claim he has created more jobs than Obama.

Ari Berman is the author of Herding Donkeys: The Fight to Rebuild the Democratic Party and Reshape American Politics, out now in paperback.