There are noticeable differences between reviews collected from different regional Amazon sites, in both average helpfulness ratio and review variance (Table 3). The review dynamics in the U.K.
and Japan communities appear to be less controversial than in the U.S. and Germany. Furthermore, repeating the analysis from Section 3 for these three new datasets reveals the same qualitative patterns observed in the U.S. data and suggested by the model introduced in Section 5. Curiously enough, for the Japanese data, in contrast to its general reputation of a collectivist culture [4], we observe that the left hump is higher than the right one for reviews with high variance, i.e., reviews with star ratings below the mean are more favored by helpfulness evaluators than the respective reviews with positive deviations (Figure 6). In the context of our model, this would correspond to a larger proportion of negative evaluators (balance p < 0.5).