Bill Kristol, who writes for The Weekly Standard, has an interpretation of some Fox News poll numbers which suggest Mitt Romney needs to put forward an economic plan. Maybe yes, maybe no.
If you believe, as Romney's campaign staff do, that this election is just a referendum on Obama's performance, no plan is necessary and putting one forward would turn off people whose interests weren't included in that plan.
If you believe that the election is a battle between competing economic plans, Obama's and Romney's, then Romney needs a plan and at this point hasn't put one forward in any detail.
I'm not sure who is correct. I do understand that newsies like Bill K. would like to have plan details to paw over. Their needs may not be the same as the needs of the voters.