Not really. If you consider the fact that thanks to automation, the number of factory workers in the US has dropped considerably in the past century. A large workforce would be counter productive in todays society, yes it works in places like China but that's not how we operate.
Plus paying people to have kids would increase the national debt, plus people would take advantage of it like some programs we already have.
Also more parents could lead to fewer of our generation in the workforce due to child care costs. Putting one or two kids in daycare is alright but 5-6 is too costly. So one parent would be home with the kids and the other would be working themselves to death to support them.
And finally there's better options to improve our economy, more grants for small business, researching cutting edge technology, or tax breaks for the middle and lower class. Many of Americas richest people, from carnegie and the vanderbiilts were only rich because they had an idea and took a chance, Bill Gates has done that too. Now if the government provided even the smallest support, imagine the technologies and companies that would end up being world leaders could potentially be started, in your average american garage.