A "Public Goods" Game

Each person starts with a "bank" of 10 points. Imagine that these points represent something of value (e.g. 100 dollars per point). We will play a series of "rounds" of a game. Each round has the following structure.

1. At the start of the round, each person writes in secret how much they will contribute to a "public pot"; this amount cannot be more than your current bank. You will also write a copy of this number on a separate piece of paper anonymously to be handed to the administrator.
2. These papers will be passed to the game administrator and shuffled.
3. The administrator will sum the combined amounts of contributions, add 10% of the total to this amount, and divide the resulting number by the number of people playing, regardless of level of contribution. This latter amount will be announced and is called the "distributed amount." The administrator will also announce the different amounts that were contributed.
4. You will then: subtract your contributed amount from your bank and add the distributed amount to your bank.
5. The game continues until the administrator announces the last round of play.