  We analyze the effect of the Pauli-Fierz mass term on a recently established,
new massive gravity theory in three space-time dimensions. We show that the
Pauli-Fierz mass term makes the new massive gravity theory non-unitary.
Moreover, although we add the gravitational Chern-Simons term to this model,
the situation remains unchanged and the theory stays non-unitary in spite that
structure of the graviton propagator is greatly changed. Thus, the Pauli-Fierz
mass term is not allowed to coexist with mass-generating higher-derivative
terms in the new massive gravity.
