Experimental Econ

At the individual level, they’re trying to categorize subjects into two types: free-riders and unconditional full contributors. They use a conservative method for classification. Subjects are labeled as free-riders if, in all but one of the first 14 periods, they contributed 10 tokens or less. On the flip side, a subject is classified as an unconditional full contributor if, in all but one of the first 14 periods, they contributed 90 tokens or more. The final period is excluded to eliminate endgame effects and allow for some deviation from prescribed behavior.

For the remaining subjects, they look for evidence of conditional cooperation. They calculate the correlation between a subject’s contribution and the lagged average contribution in their neighborhood. Subjects with significant correlations are classified as conditional cooperators, while the rest are classified as others. The distribution of these behavioral types differs between subject pools, with more conditional cooperators in one pool and only two unconditional full contributors in another.

They delve deeper into conditional cooperation, plotting the average contribution over time for classified types, considering their immediate neighborhood composition. Notably, players with a free-rider neighbor tend to converge towards free-riding faster. However, the presence of an unconditional full contributor doesn’t seem to have a comparable effect on increasing contributions from players in their neighborhood. Conditional cooperators with certain neighbor types also show a pattern of declining contributions over time.

In simple terms, the passage talks about a study on different types of contributors in a group. They used statistical methods to analyze the impact of various factors on contributions to the group. Here are the main findings:

There are significant differences in the levels of contributions among different types of contributors (classified as F-F, U-U, U-C, U-O, C-C, C-O, O-O), especially when there is an unconditional type (free-rider or unconditional full contributor) nearby.

The time period doesn’t significantly affect the F-F category, but for other types, there’s a significant negative effect over time.

The proximity to a free-rider influences contributions. Players closer to a free-rider contribute less, and this effect is stronger with closer proximity.

Proximity to an unconditional full contributor has the opposite effect, with closer proximity leading to higher contributions.

The study explores specific group compositions, like those with a single free-rider or adjacent unconditional full contributors, to understand their impact on behavior.

In essence, the research suggests that the behavior of group members is influenced by the presence of free-riders or unconditional contributors in their vicinity, and this impact varies based on the type of contributors and time.