The mayor's office says the problem is the increase in the intensity of driving by many more hire cars. Those have increased by 60 per cent in the past few years. There are already many more Uber drivers – about 20,000 – than the 13,000 yellow cabs registered. The mayor says this means many more miles being driven more often around clogged streets, requiring a study of the impact.

A city council vote on this is imminent. No truce is expected.

Broader political struggle

But the New York City brawl is just one outbreak of a much broader political struggle in how to treat the rise of new "sharing economy" services and what they mean for the future of jobs, working conditions and protection. Just as in Australia, the debate over the type of jobs and pay that will be available in a digitally connected world is dominating the domestic economic political agenda.

Republican presidential candidates like Jeb Bush, for example, use the popularity of Uber as a proxy for the necessary rise of American innovation and entrepreneurism triumphing over protectionism and excessive regulation. Bush is a proud Uber user and was keen to demonstrate it on a recent trip to San Francisco, the original home of new web-based services, as well as being a Democratic stronghold.

It's a deliberate Republican tactic to lure away younger voters who get "the sharing economy" and its infinite possibilities as a form of consumer revolution that can't be stopped.

Bush's republican competitor from Florida, Mario Rubio, is an equally loyal Uber passenger and is equally enthusiastic about defining the example of Uber as a model to escape the thicket of regulation strangling opportunities for economic growth and jobs. A chapter in one of his books is called "Making America safe for Uber". He denounces county regulations in Miami-Dade that officially ban the ride service – although naturally it is still available because Uber just pays the fines there, as it does elsewhere.

The leading Democratic candidate, Hillary Clinton, is more discreet in any direct mention of Uber in her campaign speeches. She knows she can't afford to look old-fashioned in an economy that is changing so rapidly and where consumer expectations of service are also being constantly transformed. But she also wants to talk about the need to maintain some of the more traditional conditions and protection for American workers.


That includes looking at how to adapt best to the rise of unregulated and often part-time work in such new industries.

More vociferous

The US unions are, naturally, far more vociferous on the threat that this sort of new economy poses, rather than the opportunities it offers.

This also feeds into the perceived squeeze on the traditional strengths of the middle class, including the prospect of access to well-paid, full-time employment. In the US, the land of optimism about the future, polls show that for the first time parents don't expect their children's lives to be better than theirs. A big part of that is related to doubts about the sorts and number of jobs that will be available, given what's happening to technology and the economy.

Clinton, like other Democratic politicians, has to sell the message that job protection and innovation are both necessary in any vibrant economy. It's a tricky line to negotiate. Union leaders are apparently pushing her to be more direct in her criticism of new services when they compromise the economic security of workers used to more traditional employment and conditions. The New York Times says she has yet to use Uber and, no doubt, she will never need Airbnb for accommodation.

But the daily experience of tens of millions of Americans is just the reverse.

For all the references by Joe Hockey to the implications for tax revenue, the political and economic significance of services like Uber remains a more muted conversation in Australia. Not for much longer.