This note provides answers to some of the questions people asked over the years about Chen and Plott (JPubE 1996).


  1. The exchange rate is 150 francs = $1.
  2. The experimental treatments (gamma=1, 100) were conducted sequentially. Subjects were first given the instructions, payoff tables and record sheet of the first treatment. After 30 rounds of the first treatment, they were given the payoff tables and record sheet for the second treatment, which lasts for another 30 rounds.
  3. When we wrote up the instructions, we worked from Isaac, McCue and Plott (JPubE, 1985).
  4. Note in the data file, sometimes the “round” variable skip a round, so you might end up with 31 rounds for the first treatment, which is actually 30 rounds because round n was skipped. The key variable to differentiate the treatment is “ref” (see below).
  5. On the payoff tables: ID:1 refers to subject type 1.
  6. Payoff tables: ref.1 = gamma 1 and ref. 2 = gamma 2
  7. Data file format: Round Ref Id Xi Si Oi Pi, where

Round = round number

Ref = treatment, where 1 means gamma=1,  and 2 means gamma=100.