The Listener editorial:
New Zealand’s electoral cycle is too short. Since 1935 there have been only two single-term governments. The second Labour Government (1957-60) was hammered for its infamous Black Budget, and the third Labour Government (1972-75) had the misfortune of leader Norman Kirk dying in office and being replaced by the less popular Bill Rowling.
There is no single reason that voters usually give the government a second term, but it is possible to speculate on the reasons. One is that the public thinks three years is insufficient time for the new incumbents to prove themselves. Changing the course of a heavily laden ship of state is a slow business, whichever direction you point it. Three years is a short time in which to judge the success or failure of complex new policies. Another reason may simply be that generally public fatigue takes longer than three years to set in. Also, voters may not want another big round of change visited on the country so soon after the last round.
I agree that the length of the term is why so few Governments get tossed out after one term. It is interesting that no National Government has ever failed to get a third term.
Ministers in a new government spend the first year getting to grips with their portfolios. Currently, the third year is dominated by its re-election chances, with only relatively timid policy changes. That leaves precious little time in between to do anything, particularly on important matters that require a lot of consultation or that might be unpopular. A four-year term would allow governments more chance to get things done that often should be done, but are neglected.
This is the strongest argument for change. A 33% increase in the parliamentary term would lead to 100% increase in time for quality policy development etc.