Refers to the tendency for the same dyads to keep interacting. For directed
events, the next sender and receiver are equal to the previous sender and
receiver. For undirected events, the next actor pair is equal to the current
actor pair. For each timepoint t, the psABAB statistic is equal to one for
the dyads that will create the participation shift if they would occur in
the edgelist at time t and equal to zero for the dyads that will not create
this participation shift. If consider_type is set to TRUE, the type of the
two subsequent AB events have to be equal. If it is set to FALSE, the
participation shift is set to one for every AB event, regardless of the
event type. If multiple events in the edgelist occur at the same time point,
the order of these events determines whether the p-shift is observed.