On Wikipedia, the largest online encyclopedia, editors who contribute to the same articles and exchange comments on articles' talk pages work in collaborative manner engaging in communication about their work. Thus they can be considered as peers who are likely to influence each other. In this...

This paper is concerned with exploring the implications of replicability issues over the medical innovation process. Each research setting is characterized by a specific level of replicability, variability increasing with the complexity of the testing settings. The study introduces new measures...

In markets with search frictions, consumers can acquire information about goods either through costly search or from friends via word-of-mouth (WOM) communication. How do sellers' market power react to a very large increase in the number of consumers' friends with whom they engage in WOM? The...

Consumers can acquire information through their own search efforts or through their social network. Information diffusion via word-of-mouth communication leads to some consumers free-riding on their 'friends' and less information acquisition via active search. Free-riding also has an important...

I quantify spillovers of attention in a network of content pages, which is challenging, because such networks form endogenously. I exploit exogenous variation in the article network of German Wikipedia to circumvent this problem. Wikipedia prominently advertises one featured article on its main...

Peer influence through word-of-mouth (WOM) plays an important role in many information systems but identification of causal effects is challenging. We identify causal WOM effects in the empirical setting of game adoption in a social network for gamers by exploiting differences in individuals'...

Endogeneity in network formation hinders the identification of the role 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...

This paper analyzes the impact of network externalities on R&D competition between an incumbent and a potential entrant. The analysis shows that the incumbent always invests more than the entrant in the development of higher quality network goods. However, the incumbent exhibits a too low level...

This paper studies the incentives to undertake uncertain R&D initiatives in a dynamic duopoly network industry. It is shown that network externalities positively affect the incentives to invest in R&D. In the model, competition resembles a preemption race and, therefore, market performance...

We develop a model of R&D competition between an incumbent and a potential entrant with network externalities and durable goods. We show that the threat of entry eliminates the commitment problem that an incumbent may face in its R&D decision due to the goods? durability. Moreover, a potential...