Why goofing off boosts productivity

It seems like the study is as of yet unpublished. Google Scholar didn't turn up anything, and the researcher's web page doesn't list it.

http://www.managementmarketing.unimelb.edu.au/who/staff.cfm?...

Only half true. It did link to a University of Melbourne page, which is slightly more precise and is based on an interview with a researcher in the field:

http://uninews.unimelb.edu.au/news/5750/