Although the economic success of Amazon Prime has been widely reported in the mass media, few empirical studies have carefully quantified the economic value, consumer welfare impacts, or public policy implications of the subscription program. This study contributes to this economic literature by...

A lack of platform-level competition among digital marketplaces can result in socially inefficient platform design and meaningful welfare losses, even independent of actively anticompetitive behavior. To illustrate the first-order effects platform design can have on competitive outcomes, I...

A breakdown frontier is the boundary between the set of assumptions which lead to a specific conclusion and those which do not. In a potential outcomes model with a binary treatment, we consider two conclusions: First, that ATE is at least a specific value (e.g., nonnegative) and second that the...