You don't have to look far in the political news to find a story about mates doing favours for mates.

But while some cases of political mateship reach the front page, many of them slide through in the grey area of 'how things work'.

But are backroom favours and a revolving door between regulators and  the industries they govern really a natural part of doing business?

Rigged, by Cameron K Murray and Paul Frijters looks at the game of mates in Australia and sets out to explain the cost.