  In the power scale, the asymptotic behavior of the singular values of a
compact Hankel operator is determined by the behavior of the symbol in a
neighborhood of its singular support. In this paper, we discuss the
localization principle which says that the contributions of disjoint parts of
the singular support of the symbol to the asymptotic behavior of the singular
values are independent of each other. We apply this principle to Hankel
integral operators and to infinite Hankel matrices. In both cases, we describe
a wide class of Hankel operators with power-like asymptotics of singular
values. The leading term of this asymptotics is found explicitly.
