摘要：We study the implications of uncertainty for in.ation targeting in a dynamic
set-up. Using Svensson’s in.ation forecast targeting model, we
compare the Brainard conservative principle to a more active monetary
policy rule, derived from a two-step optimisation procedure. Our analysis
points to a trade-o¤ between the ability to control expectations and the
introduction of greater variability in the system. We show that Brainard′s
attenuation principle is optimal only in a backward looking set-up where
there is no role for expectations in the determination of in.ation equilibrium.
On the other hand, we show that in a forward looking model,
Brainard’s conservative principle may produce instability, because of its
inability to control expectations. A more aggressive rule, like the one derived
in the paper, can instead provide greater stability because it provides
for a better and more direct management of expectations, despite the uncertainty
in the transmission parameters. In that respect, we show that
there are conditions under which the bene…ts of tying down expectations,
more than compensate the costs of having to overuse the instrument.
