The number of unionists, farmers and businesspeople in Parliament is falling, as MPs increasingly enter Parliament with a varied career path, new analysis shows.
The study by political researcher Geoffrey Miller and PR expert Mark Blackham showed that the two major parties were no longer dominated by MPs from traditional backgrounds.
They were increasingly being replaced by "beltway" MPs who had a background in government or politics or by "generalists" - people with no specific career experience.
"This research crushes common narratives we use to define disagreements in Parliament," Mr Miller said.
"While the battles may still be talked about as business versus unions, MPs have little experience in these fields."
The analysis showed that National MPs were most likely to come from a business background (15 per cent) followed by government roles (14 per cent) and farming (10 per cent).
Labour MPs were most likely to have had multiple roles (25 per cent), followed by iwi roles (16 per cent) and government (13 per cent).
Labour had a relatively low number of MPs with a business background, with just six falling into this category.
The most common category of MPs was those with no single career. Twenty-three out of 121 MPs fell into this category.
Nineteen MPs' main career was in business while 15 MPs' primary career had been in a government or political role.
The rise of "generalists" reflected broader social shifts, the researchers said, as people were now more likely to do a range of jobs in their lifetime.
Another trend was the growth in people who treated politics as an employment option, rather than a calling.
A total of 34 MPs had dabbled in political jobs at some stage.
In all, 10 MPs were considered "career politicians" with no experience outside of Parliament.
"Politicians portray themselves as ordinary people, but our findings show many of them are anything but," Mr Miller said.
"Across the spectrum, previous work experience for many MPs increasingly consists of working for a political party in Wellington, in a role funded by the taxpayer."
What did MPs do before Parliament?*
Politics or government roles: 16%
Foreign affairs: 4%
Maori role: 4%
*MPs can be in more than one category