Free as in liberated.  Here’s the opening paragraph:

I wrote this paper with the recognition that it is unlikely to be accepted for publication. There is something liberating about writing a paper without trying to please referees and without having to take into consideration the various protocols and conventions imposed on researchers in experimental economics (see Rubinstein (2001)). It gives one a feeling of real academic freedom!

The paper reports on long-running experiments relating response times to mistakes in decision-making.