Paths or outcomes

How do we decide what a pathway is vs. an outcome? I can imagine that in medicine this is fairly clear–for example I may want to understand the impact of a drug, and I can model the physical pathways I expect that drug to alter a body’s chemistry, and then I can model how the patient responds to that change. This is a clear oversimplification, but as a stylized description I think it’s alright.

But in social sciences we often have outcomes that are pathways to more outcomes! For example, we might be interested in how a person accumulates wealth, but we might also be interested in