We unveil collective effects induced by imitation and social pressure byanalyzing data from three different sources: birth rates, sales of cell phonesand the drop of applause in concert halls. We interpret our results within theframework of the Random Field Ising Model, which is a threshold model forcollective decisions accounting both for agent heterogeneity and socialimitation. Changes of opinion can occur either abruptly or continuously,depending on the importance of herding effects. The main prediction of themodel is a scaling relation between the height h of the speed of variation peakand its width $w$ of the form h ~ w^{-kappa}, with kappa = 2/3 for wellconnected populations. Our three sets of data are compatible with such aprediction, with kappa ~ 0.62 for birth rates, kappa ~ 0.71 for cell phones andkappa ~ 0.64 for clapping. In this last case, we in fact observe that someclapping samples end discontinuously (w=0), as predicted by the model forstrong enough imitation.
展开▼
机译：我们通过分析三种不同来源的数据来揭示由模仿和社会压力引起的集体效应：出生率，手机销售和音乐厅的掌声下降。我们在随机场伊辛模型的框架内解释我们的结果，该模型是考虑了代理异质性和社会模仿的集体决策的阈值模型。取决于羊群效应的重要性，观点的改变可以突然或持续发生。该模型的主要预测是变化速度峰值速度的高度h与形式为h〜w ^ {-kappa}的宽度$ w $之间的比例关系，其中kappa = 2/3。我们的三组数据与这种预测相符，出生率kappa约0.62，手机kappa约0.71，拍手kappa约0.64。在最后一种情况下，我们实际上观察到一些拍手样本不连续结束（w = 0），这是模型为足够强的模仿所预测的。
展开▼
