Social media , information , knowledge , spillovers , networks , natural experiment
Abstract:
Endogeneity in network formation hinders the identification of the role that
social networks play in generating spillovers, peer effects and other externalities.
This paper tackles this problem and investigates how the link network between
articles on the German Wikipedia influences the attention and content generation
individual articles receive. Identification exploits local exogenous shocks on a small
number of nodes in the network. It can thus avoid the usually required, but strong,
assumptions of exogenous observed characteristics and link structure in networks.
Exogenous variation is generated by natural and technical disasters or by articles
being featured on the German Wikipedia’s start page. The effects on neighboring
pages are substantial; I observe an increase of almost 100 percent in terms of both
views and content generation. The aggregate effect over all neighbors is also large: I
find that a view on a treated article converts one for one into a view on a neighboring
article. However, the resulting content generation is small in absolute terms.
My approach also applies if, due to a lack of network data, identification through
partial overlaps in the network structure fails (e.g. in classrooms). It helps bridge
the gap between the experimental and social network literatures on peer effects.
Das Dokument wird vom Publikationsserver der Universitätsbibliothek Mannheim bereitgestellt.