Central bank purchases of government bonds

We develop a microfounded model, where agents have the possibility to trade money for government bonds in an over-the-counter market. It allows us to address important open questions about the effects of central bank purchases of government bonds, these being: under what conditions these purchases can be welfare-improving, what incentive problems they mitigate, and how large these effects are. Our main finding is that this policy measure can be welfare-improving, by correcting a pecuniary externality. Concretely, the value of money is increased as central bank's purchases of government bonds induce agents to increase their demand for money, which is welfare-improving.