Direct and indirect benefits of introducing purchase verification in e-commerce platforms: Evidence from a natural experiment

Online e-commerce platforms struggle to create and maintain high quality reputation systems. One promising option is the``Verified Purchase''(VP) badge, which confirms that the user reviewing a product actually purchased the product from the platform. Previous works comparing reputation platforms that require purchase verification with platforms that do not offer purchase verification found that review manipulation is easier in the latter. But what happens when purchase verification is optional (VP-optional)? Even further, how does introducing purchase verification alter review and reviewer characteristics?