  In this article a condition is given to detect the containment among thick
subcategories of the bounded derived category of a commutative noetherian ring.
More precisely, for a commutative noetherian ring $R$ and complexes of
$R$-modules with finitely generated homology $M$ and $N$, we show $N$ is in the
thick subcategory generated by $M$ if and only if the ghost index of
$N_\mathfrak{p}$ with respect to $M_\mathfrak{p}$ is finite for each prime
$\mathfrak{p}$ of $R$. To do so, we establish a "converse coghost lemma" for
the bounded derived category of a non-negatively graded DG algebra with
noetherian homology.
