We owe an initial formal specification
to Pitkin, who—despite misgivings about
formalizations—observed that democratic responsiveness
includes, in one way or another,
(a) authorization of a representative by those
who would be represented, and (b) accountability
of the representative to those represented.
Building on Pitkin, D. Castiglione &
M.E. Warren (unpublished manuscript; see
also Rehfeld 2006) characterize these relationships
as follows: