Now, economic forecasting is an inexact science, to say the least, and things could turn out better than the report predicts. But they could also turn out worse. The report itself acknowledges that “some private forecasters anticipate unemployment rates as high as 11 percent in the absence of action.” And I’m with Lawrence Summers, another member of the Obama economic team, who recently declared, “In this crisis, doing too little poses a greater threat than doing too much.” Unfortunately, that principle isn’t reflected in the current plan.

So how can Mr. Obama do more? By including a lot more public investment in his plan  which will be possible if he takes a longer view.

The Romer-Bernstein report acknowledges that “a dollar of infrastructure spending is more effective in creating jobs than a dollar of tax cuts.” It argues, however, that “there is a limit on how much government investment can be carried out efficiently in a short time frame.” But why does the time frame have to be short?

As far as I can tell, Mr. Obama’s planners have focused on investment projects that will deliver their main jobs boost over the next two years. But since unemployment is likely to remain high well beyond that two-year window, the plan should also include longer-term investment projects.

And bear in mind that even a project that delivers its main punch in, say, 2011 can provide significant economic support in earlier years. If Mr. Obama drops the “jump-start” metaphor, if he accepts the reality that we need a multi-year program rather than a short burst of activity, he can create a lot more jobs through government investment, even in the near term.

Still, shouldn’t Mr. Obama wait for proof that a bigger, longer-term plan is needed? No. Right now the investment portion of the Obama plan is limited by a shortage of “shovel ready” projects, projects ready to go on short notice. A lot more investment can be under way by late 2010 or 2011 if Mr. Obama gives the go-ahead now  but if he waits too long before deciding, that window of opportunity will be gone.

One more thing: even with the Obama plan, the Romer-Bernstein report predicts an average unemployment rate of 7.3 percent over the next three years. That’s a scary number, big enough to pose a real risk that the U.S. economy will get stuck in a Japan-type deflationary trap.

So my advice to the Obama team is to scrap the business tax cuts, and, more important, to deal with the threat of doing too little by doing more. And the way to do more is to stop talking about jump-starts and look more broadly at the possibilities for government investment.