Murdoch's dynastic power play is a warning to rein in the super rich - Will Hutton

We live in an era of private dynasties. America's billionaires are worth a cool $5.5tn at the last count. Three Amazon's Jeff Bezos, Tesla's Elon Musk and Facebook's Mark Zuckerberg - are worth over a staggering $500bn between them. Americans dominate the global billionaire league table: Britain has none in the top hundred. But we still have enough to cause concern.

- Will Hutton

Individuals who have resources on this scale change the dynamics of the societies in which they live, as the US increasingly dramatises. Their spending pulls economies out of kilter so that too much production is directed towards opulent, useless baubles, but, more dangerously, it spills over into buying political influence - directly in the political process and indirectly via media ownership. Unconstrained, the impact can only grow in the decades ahead, a phenomenon of which the dynastic founders are well aware, even if the wider public is not.

A dynastic courtroom drama to unfold next month in Reno, Nevada - hitherto secret but exposed by the New York Times last week - will further shine light on the new realities. Rupert Murdoch, the 31st richest billionaire in the US, and controller of a vast media empire that ranges from Fox News in the US, the Times and the Sun in Britain, to the Australian, is petitioning to change the terms of an irrevocable trust. It currently determines that after his death his four eldest children will have equal voting rights in the strategic and editorial control of his empire. The court hearing is his effort to change the trust and instead confer control on the child he considers most reliably rightwing, his son Lachlan.