This paper explains why platforms such as Amazon and Visa rely predominantly on ad-valorem fees, fees which increase proportionally with transaction prices. It also provides a new explanation for why ad-valorem sales taxes are more desirable than specific taxes. The theory rests on the ability...

This paper investigates a puzzle and possible policy concern: Why do platforms such as eBay and Visa that enable the trade of goods of different unobserved costs and valuations rely predominantly on linear ad-valorem fees, that is, fees that increase in proportion to the sale price of the trades...

There can be no doubt that the FANG companies – Facebook, Amazon, Netflix and Google, as well as Twitter – have transformed society since their emergence. Like all social transformations, the changes wrought by their services have had ripple effects that are both positive and negative. On...

In this thesis, I have examined whether the current approach to competition policy is suitable for the distinct characteristics of the digital economy. It is particularly difficult to define the relevant market and rely on market share test as a proxy for market power in the digital economy...