The simple analytics of money and credit in a quasi-linear environment

Lagos and Wright (2005) demonstrate how the essential properties of a money-search model are preserved in an environment that is rendered highly tractable with the use of quasi-linear preferences. In this paper, I show that this same innovation can be applied to closely related environments used elsewhere in the literature that study insurance and credit markets under limited commitment and private information. The analysis demonstrates clearly how insurance, credit, and money are interrelated in terms of their basic functions. The analysis also leads to a heretofore neglected result pertaining to the Friedman rule. In particular, I find that the same frictions that render money essential may at the same time operate to render the Friedman rule infeasible. Thus, even if the Friedman rule is a desirable policy, an incentive-induced lower bound on the rate of deflation may nevertheless entail a strictly postive rate of inflation.