Relative Loop Activity is a path-transmission diagnostic. For each book-defined loop, the simulator looks at each adjacent pair of available variables in the loop, measures how strongly their quarter-to-quarter changes move together, and weights that link by the normalized movement of both variables. The loop score is the geometric mean of those link scores, so one weak or inactive link pulls the whole loop down. The highest-scoring loop in the current simulation is set to 100; the others are shown relative to it. A value of 70 means roughly 70% of the top loop’s measured path activity. It is not a formal loop gain, causal contribution, or percent of GDP.