Truly, there are a large number of really fascinating and unresolved issues in the optimal regulation of platform markets like Apple's and Google's App stores.

Truly, there are a large number of really fascinating and unresolved issues in the optimal regulation of platform markets like Apple's and Google's App stores. In the best case, such decisions need a mixture of theory and data. Right now the theory is very, very hard and data is limited (though agencies can compel firms to release it for within-agency analyses). We are quite far behind in our analyses of these markets compared to where we are in the analysis of horizontal (or even vertical) merger policy. These two decisions seem correct to me (and I teach antitrust/competition policy to undergrads and graduate students). This is an exciting area to watch and I would beware of any commenters who suggest that answers are obvious.