secondary variables

The parts of the System that directly impact the primary variables.

If a primary variable is health of economy, for example, a secondary variable might be average labor productivity (the output per employed worker).

Often, a single Action may have an impact on two or more secondary variables. For example, amplifying the productivity of a town by providing electricity might also produce pollution that damps a different secondary variable, the cleanliness of air, which in turn damps a second primary variable, the health of the citizens.

See also extract.

Author's note: I like pictures that have a double meaning, even obscurely. This one, for example, has both electricity and smog (from our example), and also secondary roads feeding into primary roads (aka highways), a good visualization of the relationship between primary and secondary variables.