We challenge the dichotomy of network effects and highlight that they are not an exogenous characteristic of networks, but endogenous to the decisions of network users. When users choose which activities to perform in a network, multi-activity users transform indirect into direct network effects...

Governments increasingly use changes in tax rules to combat evasion. We develop a general approach to point-identify tax compliance along with supply and demand elasticities; identification requires data on prices and quantities before and after changes in tax enforcement and a demand or supply...

In this paper, we determine how a no-surcharge rule (NSR) impacts effective prices in retail markets (prices that include any consumer payment rewards). This question is fundamentally related to policy, and we provide robust answers by considering how a variety of market structures are impacted...