I investigate whether two mechanisms leading to biased beliefs about success, overconfidence and competition neglect … making their decision. Second, I vary whether the competition group consists of all potential competitors or only of …

consumer surplus. We relate our findings to competition cases in digital markets. …

We analyze platform competition where user data is collected to improve adtargeting. Considering that users incur … overall competition is weak or if targeting benefits are low, too much private data is collected, and vice-versa. Further, we … find that softer competition on either market side leads to more data collection, which implies substitutability between …