Each session is randomly assigned to be either a Grameen-style game or a RoSCA game. In each game, players are partnered up and Player 1 is endowed with a specific amount of initial capital. Players have the opportunity to make a capital investment, but must take out a loan to do so. If Player 1 takes out a loan, their default or repayment behavior affects the options available to Player 2 in the future, and vice versa.
In the Grameen-style game, players borrow from and are punished by the bank. However, after the first period, players can borrow from each other to repay the bank.
In the RoSCA game, if the players mutually decide to play the game and invest capital, they pay a small fee to the bank upfront which will guarantee the RoSCA against default. Player 1 receives the first RoSCA loan. If they default, they receive a loan from the bank to repay the RoSCA (which they can either repay or default). If Player 1 repays the RoSCA, Player 2 will receive a loan from the RoSCA, and will face the same choices as Player 1.
The games differ because in the Grameen-style game, bank loans occur first, with player support secondary. In the RoSCA game, this pattern is reversed, with intra-player support first, and bank loans secondary. For more detail on the games, please refer to El-Gamal et al. (2015).