The discussion on own-rates, the natural rate, and Sraffa cropped again.
Andrew Lainton blogged here, followed by Nick Rowe here, Daniel Kuehn here, and David Glasner here.
It seems to me that Nick and David are more or less on the same side of the aisle. I commented on Nick's post here, and Nick provided a helpful response. I commented on Glasner here, and he gave me some good feedback.