Vox examines the Trump administration's infrastructure plans with Marc Scribner:
So where did that $1.5 trillion number come from? According to the White House, the other $1.3 trillion will be kicked in by states and private investors who can get a subsidy from the feds for financing the bulk of new projects. (The Trump administration will take on 20 percent of a project’s cost if states foot the bill for the other 80 percent, and they’re offering financing help for private investors.)
And even if you believe the size of the administration’s infrastructure plan is properly expressed in terms of how much they’re hoping other people spend along with it, “their assumptions are about as rosy as rosy can get,” says Marc Scribner, an infrastructure expert at the conservative Competitive Enterprise Institute.