At yesterday’s White House press conference, President Obama had a compelling suggestion for the press corps in attendance.

“[H]ere’s a little homework assignment for folks,” he said.”Go ask the Republicans what their jobs plan is if they’re opposed to the American Jobs Act, and have it scored, have it assessed by the same independent economists that have assessed our jobs plan. These independent economists say that we could grow the economy as much as 2 percent, and as many as 1.9 million workers would be back on the job. I think it would be interesting to have them do a similar assessment… Have those economists evaluate what, over the next two years, the Republican jobs plan would do.”

At a certain level, Obama was being deliberately coy. There is no Republican jobs plan, at least not in the formal sense. The president and his team, love them or hate them, put pen to paper — they introduced a serious and detailed plan, unveiled a bill, and allowed it to be scrutinized by independent analysts. GOP leaders, in contrast, put some vague platitudes on a website.

But to her credit, the New York Times‘ Jackie Calmes saw value in the president’s suggestion and put Obama’s proposition to the test.

Mr. Obama said that while he agreed with some of the Republicans’ proposals — for example, he recently sent three trade bills to Congress for its approval — he said they would not help the economy in the short term. Economists at private-sector forecasting firms agreed.

While economic forecasts are not definitive, in that they are predictions, Macroeconomic Advisers, a St. Louis-based firm that the Federal Reserve often uses, has projected that the Obama jobs plan could increase economic growth by 1.25 percentage points and add 1.3 million jobs in 2012. Moody’s Analytics, another firm, has estimated it would add two percentage points and up to 1.9 million jobs.

Joel Prakken, chairman of Macroeconomic Advisers, said Republicans had “reasonable ideas” but not ones that could be measured by the firm’s forecasting model. He said he believed the proposals “would have little immediate effect relative to a plan that stimulates aggregate demand” — that is, a plan like Mr. Obama’s, with tax cuts and spending programs.

Mark Zandi, chief economist at Moody’s Analytics, similarly said the Republican proposals “are generally good longer-term economic policy, but they won’t mean much for the economy and job market in the next year.” He continued: “Given the high odds of another recession in the next few months, it is vital for Congress and the administration to provide some near-term support to the economy.” [emphasis added]

None of this comes as a surprise, of course, which is probably why so few reporters took up Obama’s challenge — the results were pretty obvious.

But this realization should be important to the larger debate over the economy, shouldn’t it? With 9.1% unemployment and a genuine jobs crisis, we have two competing approaches: (a) a credible White House plan with ideas from both parties that, according to independent analyses, would boost an economy that desperately needs a hand; and (b) a vague Republican wish list of tired ideas that, as is clear after any serious evaluation, wouldn’t make matters better.

Until GOP officials come up with a sincere alternative to the American Jobs Act, why should anyone take their whining seriously?

Steve Benen

Follow Steve on Twitter @stevebenen. Steve Benen is a producer at MSNBC's The Rachel Maddow Show. He was the principal contributor to the Washington Monthly's Political Animal blog from August 2008 until January 2012.