Economists model systems to clarify:

The choice that indicates economists model systems to clarify "the relationships between exogenous and endogenous variables" captures the essence of economic modeling. In economics, exogenous variables are those that are determined outside the model and are not influenced by the internal mechanisms of the model; they can affect the system being studied. On the other hand, endogenous variables are those that are determined within the model itself as a result of the interactions among the various components of the model.

By elucidating these relationships, economists can better understand how changes in exogenous variables—like government policy, external shocks, or technological advancements—can influence the behavior of endogenous variables, such as output, unemployment, or inflation. This understanding is crucial for making predictions, guiding policy decisions, and analyzing the implications of various economic scenarios.

In contrast, while abstract concepts, the role of government, and historical events are all relevant to economic study, they do not encapsulate the fundamental purpose of modeling in the way that analyzing the relationships between exogenous and endogenous variables does. Modeling serves primarily as a tool to depict and clarify these intricate relationships, allowing economists to simulate and predict the effects of changes within an economy.