Today, many platforms rely on contributions by users to create value. While they play an increasing role in today's digital economy, little is known about how dominant user-driven platforms emerge and what determines the production of content here. We aim to extend our understanding of this...

We document a causal impact of online user-generated information on real-world economic outcomes. In particular, we conduct a randomized field experiment to test whether additional content on Wikipedia pages about cities affects tourists' choices of overnight visits. Our treatment of adding...

Do contributions to online content platforms induce a feedback loop of ever more user-generated content or will they discourage future contributions? To assess this, we use a randomized field experiment which added content to some pages in Wikipedia while leaving similar pages unchanged. We find...

Properties of blogging networks are derived from a model where bloggers devote attention to others, produce content for others, and exchange attention with content within their network of relations. The predictions from the model are tested with a novel dataset from LiveJournal, a major blogging...

We document a causal influence of online user-generated information on realworld economic outcomes. In particular, we conduct a randomized field experiment to test whether additional information on Wikipedia about cities affects tourists' choices of overnight visits. Our treatment of adding...

Economic literature acknowledges the impact of immigration on cross-border patenting and scientific publications. However, the role of immigration ows in the dissemination of knowledge in a broader sense is yet to be assessed. In this paper, I estimate the effect of immigration on the...

In this paper, we address the impact of surging unemployment on online public good provision. Specifically, we ask how drastically increased unemployment affects voluntary contributions of content to the online encyclopedia Wikipedia. We put together a monthly country-level data set, which...

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...

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...