The study was merely commissioned by the FCC, but it was actually conducted by Harvard's Berkman Center for Public Policy. And your curt comment neatly avoids actually evaluating this very well-done study. I've done my own analyses of the data (which is mostly all publicly available from the OECD) and found similar conclusions (for example: about 68% of the variance in price of "fast" connection (12-36Mb/s) in the OECD is attributable to the presence of various government regulations, including LLU, as is about 30% of the variance in price per mbit). If you doubt their methodology or results, I invite you to look at the data and make your own conclusions.

How can you possibly isolate something to a percentage point that involves things as nebulous as "various government regulations" operating on vast industries spanning multiple countries? My skepticism meter is off the charts here.

It's not actually that nebulous (I was simplifying because it seemed more appropriate for the setting than to give a thorough discussion of the relevant analysis). The technique, though, is regression analysis, which is widely used in econometrics (amongst other fields) to gauge the marginal effect of various variables. Obviously the exact percentage should be taken with a grain of salt, but those numbers (which are significant at 5% confidence) clearly demonstrate the point.

Again, the Berkman Center's study is very well-done, and if your skepticism remains I encourage you to at least skim it. Otherwise, you're arguing from a position of ignorance and are contributing little to this discussion.