Hi Angela, I think you've captured a very important point here regarding the validity of behavioral big data (BBD). Enjoyed reading your paper. We are also thinking about ways to quantify variation due to the platform structure and variation due to innate preferences. As you mention, it is very difficult to separate the two and there may be metaphysical arguments against the very idea of "innate preferences," anyway. In case you're interested, here's a link to a blog post that discusses some of these issues: https://medium.com/swlh/a-information-based-philosophical-view-of-machine-learning-and-the-digital-person-b54736b276a9?source=friends_link&sk=8bf2b707cdfc8205ac7a6eb8429d62a5