Skip to main content

Table 1 Meaning of symbols

From: Groupwise information sharing promotes ingroup favoritism in indirect reciprocity

Symbol

Meaning

M

Number of groups

θ

Probability that a donor and recipient in a one-shot game are in the same group

r∈{G, B}M

Reputation vector of a player in the eyes of M observers

p k (r)

Probability that a player in group k has reputation vector r

p−k(r)

Probability that a player outside group k has reputation vector r

σ(r)∈{C, D}

Donor’s action to a recipient having reputation r∈{G, B}

Φ r (a,r′)

Probability that an observer assigns reputation r∈{G, B} to a donor selecting action a∈{C, D} to a recipient having reputation r′∈{C, D}

pin(r)

Probability that a player in the eyes of an ingroup observer has reputation r

pout(r)

Probability that a player in the eyes of an outgroup observer has reputation r