This chapter is devoted to the macroeconomic system of the economy, a subject whose relevance to comparative economics has largely remained unexplored in the literature. Only the broad differences between the fiscal and monetary systems of market and centrally planned economies have received any degree of attention. Here we avoid placing primary emphasis on the dichotomous comparison of these macro-systems but seek to identify significant system variants within the broad range of institutions represented in centrally planned and market economies. We also stress the common elements among all systems, due to the aggregate macroeconomic identities that they must satisfy. The penultimate section of the chapter is given over to the analysis of the dependency of macroeconomic policies on political factors, which may be exogenous to the economy or may be endogenously determined by the outcomes of economic processes. In the last section, we briefly consider the effect of rules coordinating the macroeconomic decisions and policies of national governments within a group of cooperating nations. As in previous parts of the monograph, we first tackle relatively simple concepts from which we construct more complicated aggregates.