21 Changes to the PTA have tended to reflect actual Bank practice at the time, but have also often been initiated by the government of the day. The Bank has seen several government reviews of its framework, often in response to macroeconomic developments. And this is 18 See for example Rogers (2013) and Dunstan (2014). 19 Kamber et al.
(2015) note that while the importance of coordination depends on the magnitude of the  externalities that each policy has on the other, how large these effects are is currently not well understood. Since the Bank is jointly responsible for both policies, these trade-offs should necessarily influence the settings of both monetary and macroprudential policies.