创新扩散中的同伴效应:基于农业新品种采纳的案例分析

Peer Effects in the Diffusion of Innovation:A Case Study on the Adoption of a New Crop Variety

创新扩散过程中普遍存在着基于社会网络关系的同伴效应。在明确界定同伴效应的基础上,提出了一个分析创新扩散中不同形式同伴效应的一般性理论框架,将同伴效应分解为信息效应、经验效应和外部性效应,并将其用于研究一个农业新品种在10个自然村持续10年的创新扩散过程,深入解析三种同伴效应及其对农业新品种扩散的影响。分析发现:三种同伴效应分别在整个创新扩散过程的早期、中期和后期主导创新的扩散,且各自经由不同类型的社会关系发生。信息效应可以促使极少数创新意愿较高的个体采纳创新,但是难以诱发大规模的创新扩散;经验效应相对较强,它通常促使“关键大众”的形成;外部性效应则促使创新意愿较低的一部分个体也跟进。因此,应基于社会互动,动态地、差异性地利用同伴效应来促进创新扩散,在农技推广中适时地激励经验分享行为。

Peer effects based on social network relations are prevalent in the diffusion of innovations.Based on a clear definition of peer effects,this paper presents a theoretical framework to study peer effects in the diffusion of innovations.Peer effects are split into information effect,experience effect and externality effect.This framework is applied to the case of the 10-year diffusion of a high-value crop in a rural community and the impact of the three effects on the diffusion of the high-value crop are analyzed in detail.The analyses indicate that the three effects dominate the diffusion process in its early,intermediate and late phases respectively and occur through different social networks.Information effect can motivate a very small number of individuals with a high willingness to innovate but is not able to provoke the majority to adopt innovation.Experience effect is relatively stronger and often facilitates the formation of a“critical mass”.Externality effect pushes the lagged to follow the suit.According to the theoretical framework and findings from the case study,suggestions for improving agricultural extensions and farmers’adoption of agricultural technologies are made.