Fiscal and monetary systems do not exist without specific institutional design. In this regard, there is a difference between the facts of actual institutional design, and conceptual distillations that infer hypothetical design. Any overall view of actual treasury and central banking operations should be portrayed accurately in this respect. For example, there is a difference between the consolidated view of separate Treasury and central bank institutions as they actually operate, versus the view of an implied but unstated counterfactual in the sense of a unified institution. The actual operation of separate institutions is not at all the same as that implied by a unified counterfactual institution.Read it at Modern Monetary Realism
Treasury and the Central Bank – A Contingent Institutional Approach
Note: JKH cites Marc Lavoie's The monetary and fiscal nexus of neo-chartalism: A friendly critical look (2011), which brings up a criticism of MMT's consolidation of the Treasury and central bank functions (begins at p. 10). This is the point that JKH is attempting to clarify through an analysis of actual operations.