Externalities in Knowledge Production: Evidence from a Randomized Field Experiment

Are there positive or negative externalities in knowledge production? We analyze whether current contributions to knowledge production increase or decrease the future growth of knowledge. To assess this, we use a randomized field experiment that added content to some pages in Wikipedia while leaving similar pages unchanged. We find that adding content did not have a sizable impact on long-term content growth, neither in terms of quantity or quality. However, it increased editing activity in the first two years. Our results have implications for information seeding and incentivizing contributions. They imply that additional content may inspire future contributions in the short- and medium-term, but do not generate sizable externalities in the long-term.