Diffusion in small worlds with homophily and social reinforcement: A theoretical model

We introduce homophily in a percolation model of word-of-mouth diffusion in social networks by reorganizing the nodes according to similarity in preferences for adoption of an innovation. Such preferences are described by a “minimum utility requirement” for an agent to adopt. We show that homophily removes the non-linear relation between preferences and diffusion in the standard percolation model with a high diffusion regime (“hit”) and a low diffusion regime (“flop”). Instead, in a model with perfect homophily, the final diffusion scales linearly with individual preferences: all agents who are willing to adopt, do adopt the innovation. We also investigate the combined effect of homophily and social reinforcement in diffusion. Results indicate that social reinforcement renders clustered networks more efficient in terms of diffusion size for network with strong homophily, while the opposite is true for networks without homophily. The simple structure of our model allows to disentangle the effect of social influence, homophily and the network structure on diffusion. However, the controllability of the theoretical structure comes at the expenses of the realism of the model. For this, we discuss possible extensions and empirical applications.     

西部小城镇建设现状分析及发展对策研究

西部小城镇建设中存在转移剩余劳动力能力弱,布局不合理,缺乏产业带动,基础设施建设未能满足城镇发展需要及生态环境破坏等问题。通过对小城镇目前建设现状分析,提出小城镇建设的相应对策,包括布局战略、产业战略、人力资源开发战略及基础设施与生态环境建设战略,最终达到西部地区经济效益与生态效益双赢的目的。     

风险投资与中小企业技术创新

我国中小企业发展面临许多困难 ,其中一个主要障碍是中小企业在技术创新活动中资金短缺 ,且技术创新的风险大。中小企业利用传统融资方式来寻求资金十分困难 ,而风险投资能较好地解决这个融资难题 ,促进技术创新。本文主要针对如何应用风险投资促进中小企业发展进行初步探讨 ,并提出相应的对策与建议