When assessing John Key’s legacy, context is critical.

Key came into office in late 2008 in the midst of the worst financial crisis since the Great Depression. By that time, the New Zealand economy was already in recession, with Treasury projecting sharply rising unemployment and persistent budget deficits.

In response to the GFC, governments around the world embarked on Keynesian-style stimuli, of epic proportions. Whether it was Obama’s cash for clunkers, or Rudd’s pink batts programme, the preferred prescription was to spend and, when finished, to spend more. It has left many with mountains of debt that will take generations to repay.

The aftermath of the GFC has been gruesome; littered with nations divided by inequality, rising populism, and dysfunctional governments.

During this period New Zealand faced not just one crisis, but two, with the devastating Christchurch earthquakes. Quite apart from the human costs, forecasters at the time predicted they would cause a decade of deficits.

Against this background, the Key years have been remarkable. Stable government itself has been an achievement. A simple comparison with Australia will suffice: during Key’s time as prime minster he has witnessed four leadership changes across the Tasman. Steady-as-she-goes may have been bad for our media, but it undoubtedly contributed to New Zealand’s rising business confidence, and to long term investment and growth.

The government’s fiscal discipline has also been impressive: not just by resisting the spending affliction that gripped others, but by quickly returning the government’s accounts to surplus – and healthy ones too. Again, the contrast with Australia is stark. While Bill English can take much of the credit for this achievement, it is Key who granted him the licence to be prudent.

Key’s was also a reforming government. After the Fourth Labour government, it was perhaps New Zealand’s most radical in the post-war era. The GST for income tax swap, welfare reforms (the likes of which might have brought down another government), the investment approach to social services; labour market reform, partial-privatisation, reforms in education, including national standards and charter schools: these may have occurred incrementally, but together they comprise a prodigious package of reform.

Of course, there is much more Key could have attempted. And he left many feeling he should have done so – in housing, infrastructure, education and health (not to mention superannuation).

But that he achieved as much as he did under MMP, while maintaining popular support at unprecedented levels, is truly remarkable. Along the way, his resilience and endless self-confidence proved infectious. And perhaps that will be his greatest legacy.

For a slightly different perspective, see Eric Crampton's piece, John Key, quite an underachiever.