Other countries with similar electoral systems, including Germany and Mexico, have terms of between four and six years - and what politician wouldn't opt for more time in the job?
But not so fast, say the electors. When the proposal was put to voters at referendums in 1967 and 1990, the three-year term was favoured by majorities of 68 per cent and 69 per cent.
It still has much to commend it. Those who say a three-year electoral cycle is too short contend it unreasonably limits what governments can achieve. A new government is liable to spend its first year briefing incoming ministers and prioritising what it wants to do and its third year trying not to disturb the voters before another election, leaving too little time for making changes which may be necessary, but not popular.
Those who defend the three-year term prefer it for the same reason: it limits what governments can do. A short electoral cycle is the only strong check on government actions in a nation lacking others such as a written constitution, a second chamber of Parliament or a federal system. Political power in New Zealand is centralised in a single-chamber parliamentary majority.
The case against a four-year term was stronger when all power was handed to the party that won elections under the Westminster electoral system. It is less persuasive with proportional representation. Although polling between elections may have predicted as such, no party has governed alone since the adoption of MMP. Proportional representation was always one option, with a written constitution or a second chamber, for providing checks and balances on government power. Now that we have learned to live with one, should we have another look at a four-year term?
Anything encouraging decision-makers to broaden horizons should be seen as a positive. In New Zealand, new governments are normally re-elected at least once. The country hasn't had a one-term government since 1975 and it has happened only twice in more than 125 years of party politics as we know it. Some say we already have a six-year term, with a three-year check.
In fact, most governments have been re-elected twice, lasting nine years before public mood swings against them in their final term, when people hanker for a change.
It is even possible a four-year term would bring changes of government after eight years, rather than nine.
A four-year term gives a government more opportunity to be visionary, and it is worth considering again.