We estimate the welfare associated with the Medicare HMO program, now known as Medicare+Choice (M+C). We find that the creation of the M+C program resulted in approximately $15.6 billion in consumer surplus and $52 billion in profits from 1993 to 2000 (in 2000 dollars). This program most likely...

We seek to determine the causes and magnitudes of network externalities for the automated clearing house (ACH) electronic payments system.We construct an equilibrium model of customer and bank adoption of ACH.We structurally estimate the parameters of the model using an indirect inference...

To what extent will an industry in which mergers are feasible tend toward monopoly? We analyze this question using a dynamic dominant-firm model with rational agents, endogenous mergers, and constant returns to scale production. We find that long-run industry concentration depends upon the...

We analyze the extent of network externalities for the automated clearinghouse (ACH) electronic payments system using a panel dataset on bank adoption and usage of ACH. We develop three methods. The first examines the clustering of ACH adoption. The second examines the impact of market...

I develop a dynamic model of mergers, where mergers, investment, entry, and exit are endogenous variables rationally chosen by firms to maximize expected future profits. This model differs from previous analyses in that it incorporates dynamics and endogenizes the merger process. The model...