Structural Issues

Ken Rogoff and Ed Phelps both commenting on the need to think about future growth prospects and "structual" supply-side problems.

I think they both are getting at something important, but we probably need more research (and commentary) in this area to pin things down. What are the real structural problems here? What policies would target them specifically? While Phelps suggests a few idea, it's an op-ed so they lack specifics. Even in sound-bite form, though, they don't sound like the answer to me, save the tax-credit for low-wage workers which is worth looking into.