It has become an urban legend in New Zealand that inequality is getting worse and worse.
Brian Easton adjusted the top income share database for New Zealand for the introduction of dividend imputation. This encouraged companies to distribute more dividends.
Once this measurement error was corrected by Easton, there has been no increase in top income shares in New Zealand since the 1950s. It has been a slow taper at best or a flat line.
There is a wages boom from the early 1990s after 20 years of wage stagnation, a period which some people regard as the good old days.
The return of real wages growth, and strong employment growth to boot, came straight after the Ruth Richardson horror budget and the passage of the Employment Contracts Act.
Every ethnic group experienced strong income growth as well as the graphic below shows. The rich got richer and the poor got richer too.