PROBLEMS IN CAUSAL LOOP DIAGRAMS REVISITED

The increasingly popular S and O notation in causal-loop diagrams has a serious flaw, which suggests it should be purged from educational, c onsulting, and publication practice. The flaw traces to the inability of the notation to capture correctly the influences of flows into and out of stocks, which appear implicitly in word-and-arrow diagrams. In contrast, the older notation of plus and minus signs handles the probl em well.