I am looking for a study on a particular type of public goods game. 
Public goods games are some times used to develop a better
understanding on altruism and self-interest.  In most of the research
that has been done in the field, there is an amount that is thrown
into a collective pot.  That pot is then later multiplied and divided
amongst the group (6 people or so) that is being studied.  What I am
looking for is a study that did not redistribute the pot to the group.
 I'd like to see a situation where the pot is simply donated to
charity, so none of the group members have anything to gain by
contributing to the pot.   All I need is one article/study, but it
does need to be from a reputable source, such as a peer-reviewed
journal.

For more background on this question, please see:
http://answers.google.com/answers/threadview?id=773228

Thanks