Using the theory of
{\mathbf {FS}} {^\mathrm {op}} modules, we study the asymptotic behavior of the homology of
{\overline {\mathcal {M}}_{g,n}}, the Deligne–Mumford compactification of the moduli space of curves, for
n\gg 0. An
{\mathbf {FS}} {^\mathrm {op}} module is a contravariant functor from the category of finite sets and surjections to vector spaces. Via copies that glue on marked projective lines, we give the homology of
{\overline {\mathcal {M}}_{g,n}} the structure of an
{\mathbf {FS}} {^\mathrm {op}} module and bound its degree of generation. As a consequence, we prove that the generating function
\sum _{n} \dim (H_i({\overline {\mathcal {M}}_{g,n}})) t^n is rational, and its denominator has roots in the set
\{1, 1/2, \ldots, 1/p(g,i)\}, where
p(g,i) is a polynomial of order
O(g^2 i^2). We also obtain restrictions on the decomposition of the homology of
{\overline {\mathcal {M}}_{g,n}} into irreducible
\mathbf {S}_n representations.