  We explore Chern-Simons theories coupled to fundamental ghost-like matter in
the large $N$ limit at 't Hooft coupling $\lambda$. These theories have been
conjectured to be holographically dual to parity-violating, asymptotically
dS$_4$ universes with a tower of light higher-spin fields. On $\mathbb{R}^3$,
to all orders in large-$N$ perturbation theory, we show that Chern-Simons-ghost
theories are related to ordinary Chern-Simons-matter theories by mapping $N
\rightarrow - N$ and keeping $\lambda$ fixed. Consequently, the bosonization
duality of ordinary Chern-Simons-matter theories extends to a bosonization
duality of Chern-Simons-ghost theories on $\mathbb R^3$. On $S^1 \times S^2$,
in the small-$S^1$ limit, neither $N \rightarrow -N$ nor bosonization hold, as
we show by extensively studying large-$N$ saddles of the theories with both
ghost and ordinary matter. The partition functions we compute along the way can
be viewed as pieces of the late-time Hartle-Hawking wavefunction for the bulk
dS$_4$ gravity theories.
