I re-analyzed the calibration data, looking at all 10 question averaged together (which I think is a better approach than going question-by-question, for roughly the reasons that D_Malik gives), and found that veterans did better than newbies (and even newbies were pretty well calibrated). I also found similar results for other biases on the 2012 LW survey.
If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.