3.2.2.2. Symmetric complementarity condition
Symmetric complementarity describes a condition in which both input variables behave in a similar manner in effecting the performance outcome. This condition can be further categorized as (a) critical symmetric complementarity and (b) non-critical symmetric complementarity.
The first case, critical symmetric complementarity, describes a condition in which there is incremental performance by implementing X1 and X2 simultaneously. Positive performance impact can only be achieved by the implementation of both input strategies, i.e.