  We propose a higher-order generalization of the well-known overall clustering
coefficient for triples $C(3)$ to any number of nodes. We give analytic
formulae for the special cases of three, four, and five nodes and show that
they have very fast runtime performance for small graphs. We discuss some
theoretical properties and limitations of the new measure, and use it to
provide insight into dynamic changes in the structure of U.S. airline networks.
