The typical Australian family takes home less today than it did in 2009, when Kevin Rudd was prime minister.

The shocking finding, in the latest latest wave of the Household Income and Labour Dynamics survey, helps explain a growing political divide about inequality, even though the survey itself provides mixed evidence on whether things are getting worse.

Unique among Australian surveys, HILDA has been conducted every year since 2001 by returning to the same households and tracking changes in their lives.

Funded by the Department of Social Services and managed by the Melbourne Institute, it is able to reveal what the census and other mass surveys cannot: how the life circumstances of individuals change over time.