Is the Bond Market Competitive? Evidence From the ECB's Asset Purchase Programme

We document a recurring pattern in German sovereign bond prices during the Eurosystem's Public Sector Purchase Program (PSPP): a predictable rise towards month-end, followed by a subsequent drop. We propose a sequential search-bargaining model, capturing salient elements of the PSPP's implementation, such as the commitment to transact within an explicit time horizon. The model suggests that this predictable pattern emerges as a consequence of imperfect competition among dealers who are counterparties to the Eurosystem. Predicated on the model's implications, we find that the price fluctuations are markedly accentuated: (a) for bonds specifically targeted by the PSPP, (b) during monthly intervals wherein the Eurosystem engages with a lower number of counterparties, and (c) when the Eurosystem aims for a larger purchase amount. Finally, we explore the potential consequences of our findings for the design and implementation of future asset purchase programs.