There is a bill under submission, for which comments are being invited, to reduce the size of the House of Representatives–in New Zealand, that is.
Currently there are 120 members. The proposal would cut it to 100. I will copy here the core of a comment I left at David Farrar‘s blog:
By the cube-root rule (reasonably well established in comparative electoral and legislative studies), New Zealand should have a parliament of about 159 MPs. Anywhere from 126 to 201 would be within the usual empirically observed variation for a country the size of New Zealand. So, yes, the current size is already on the small side, and 100 would be ridiculously small.
Note that I would suggest NZ increase to at least 150 or, at worst, stay at 120, independent of the electoral system. But with MMP, a small parliament means either very large districts or compromising too much on proportionality. MMP perhaps demands an optimally or even over- sized parliament even more than do “pure” FPTP or PR systems.
The argument that a cabinet would dominate such a small parliament is also a serious one (though less so under any kind of PR/coalitional system than with FPTP and single-party cabinets).
The link above places the US House size in comparative perspective, including a graph showing the cube-root relationship.