Table 3.
Raters’ guesses about players’ cooperative behaviour.
| Panel A: Summary statistics | |||
|---|---|---|---|
| Treatment (N) | Guessed split | Average correct | Accuracy |
| Round 1 guesses (actual Split = 74.5%) | |||
| None | 63.6 | 56.1 | −0.115 |
| (108) | (27.2) | (14.0) | (0.546) |
| Label | 61.0 | 58.7 | 0.238 |
| (101) | (15.9) | (8.6) | (0.363) |
| Photo | 56.1 | 55.9 | 0.214 |
| (108) | (16.8) | (8.7) | (0.348) |
| Video | 54.0 | 53.4 | 0.113 |
| (105) | (13.2) | (8.5) | (0.362) |
| All | 58.7 | 56.0 | 0.110 |
| (422) | (19.4) | (10.4) | (0.436) |
| Difference | 16.77*** | 13.49** | 48.40*** |
| Round 2 guesses (actual Split = 53.2%) | |||
| None | 60.0 | 60.2 | 0.536 |
| (108) | (18.4) | (8.2) | (0.451) |
| Label | 60.8 | 60.7 | 0.561 |
| (101) | (14.6) | (7.9) | (0.438) |
| Photo | 59.0 | 62.5 | 0.674 |
| (108) | (12.1) | (6.3) | (0.351) |
| Video | 55.4 | 61.6 | 0.606 |
| (105) | (11.1) | (6.5) | (0.352) |
| All | 58.8 | 61.3 | 0.595 |
| (422) | (14.5) | (7.3) | (0.402) |
| Difference | 8.58* | 6.55 | 7.42 |
Note: Values for guessed Split, correctness, and actual Split are percentages. Standard deviations are in parentheses. Difference reports the results of the Wald test that the treatment dummy coefficients in generalised linear model regression are equal: chi-squared with 3 degrees of freedom reported; *** p < 0.001, ** p < 0.01, * p < 0.05. These test results are robust using Kruskal–Wallis.