  We settle the question of where exactly the reduced Kronecker coefficients
lie on the spectrum between the Littlewood-Richardson and Kronecker
coefficients by showing that every Kronecker coefficient of the symmetric group
is equal to a reduced Kronecker coefficient by an explicit construction. This
implies the equivalence of a question by Stanley from 2000 and a question by
Kirillov from 2004 about combinatorial interpretations of these two families of
coefficients. Moreover, as a corollary, we deduce that deciding the positivity
of reduced Kronecker coefficients is $NP$-hard, and computing them is
$\#P$-hard under parsimonious many-one reductions.
