(e.g. to give high level of contribution when others make low contribution). The numbers of occurrences are quite high: 28% (14 out of 50) in ‘suspected’ free-riding Treatment 2 and 34% (17 out of 50) in Treatment 3. The numbers of occurrences of pro-social behaviour are lower (16% of rounds (8 out of 50) in Treatment 2 and 24% of rounds (12 out of 50) in Treatment 3). However where two of ‘partial’ consensus, three group members make the same choice, occurs on many occasions (66% of rounds (33 out of 50) in Treatment 2 and 79% of rounds (35 out of 50). In summary, social learning through communication has been used by some participants to optimise collective outcomes (by contributing high) but it has also been used by some others to optimise their individual outcomes (by on ‘free-riding’ others’ contributions). This shows that both cooperators and exist in the ‘free-riders’ experiment. In line with this finding, a relevant study using a one-off experimentation by Fischbacher et al. (2001) showed that a fraction of people are conditional cooperators (50%), another fraction are (30%) and the other ‘free-riders’ fraction are either or display no patterns. ‘hump-shaped’ contributors 4.2 Analysis using learning models To study the existence of and models of social learning, thus confirmation conformity testing Hypothesis 3, the choices of individuals in Treatments 2 and 3 are analysed. We decide to use a simple method for modelling choice making, which participants’ is based on the probability of a choice being made by an individual. The higher the probability is, the more likely the choice will be selected. These probabilities are obtained using learning models, which include both individual learning and social learning models.
(e.g. to give high level of contribution when others make low contribution). The numbers of ‘suspected’ free-riding occurrences are quite high: 28% (14 out of 50) in Treatment 2 and 34% (17 out of 50) in Treatment 3. The numbers of occurrences of pro-social behaviour are lower (16% of rounds (8 out of 50) in Treatment 2 and 24% of rounds (12 out of 50) in Treatment 3). However ‘partial’ consensus, where two of three group members make the same choice, occurs on many occasions (66% of rounds (33 out of 50) in Treatment 2 and 79% of rounds (35 out of 50). In summary, social learning through communication has been used by some participants to optimise collective outcomes (by contributing high) but it has also been used by some others to optimise their individual outcomes (by ‘free-riding’ on others’ contributions). This shows that both cooperators and ‘free-riders’ exist in the experiment. In line with this finding, a relevant study using a one-off experimentation by Fischbacher et al. (2001) showed that a fraction of people are conditional cooperators (50%), another fraction are ‘free-riders’ (30%) and the other fraction are either ‘hump-shaped’ contributors or display no patterns. 4.2 Analysis using learning models To study the existence of confirmation and conformity models of social learning, thus testing Hypothesis 3, the choices of individuals in Treatments 2 and 3 are analysed. We decide to use a simple method for modelling participants’ choice making, which is based on the probability of a choice being made by an individual. The higher the probability is, the more likely the choice will be selected. These probabilities are obtained using learning models, which include both individual learning and social learning models.
Sunitiyoso_Avineri_Chatterjee_Transportation_Research_Part_A_2011_Social_Interactions_Accepted_Version.docx