If ever we needed evidence that the Greens don’t expect to be the party of government any time soon, Richard Di Natale’s latest suite of policies provides it. A grab-bag of un-costed ideas, the policy program outlined at the National Press Club on Wednesday would be impossible to implement in government.

While most people were focussed on the proposal to turn the RBA into a retail mortgage-lender, the Greens’ embrace of the Universal Basic Income (UBI) deserves scrutiny.

The UBI is perhaps the most widely supported idea in fashion on the progressive side of the political debate, so it’s no surprise to see the Greens jump onboard. But it is no solution to inequality, and far from a progressive answer to the problems in our current tax and transfer system.

After a comment segment aired on Sunrise, The Project aired a piece on a universal basic income, with Waleed Aly offering a defence of the policy.

Why do people think it is? Proponents of a UBI claim that it would replace our current uneven rates of income support with one payment, set at a rate that provides a decent standard of living. Further, they claim that, by being paid on a non-means tested basis to all adults regardless of their employment status, the UBI would remove the “stigma” associated with welfare. It’s also asserted that it would strengthen the power of workers by enabling them to “walk away” from work that is badly paid or offers poor conditions.

To deliver all this, a UBI would need to be provided to every Australian adult, at least at the rate of the age pension, currently $814 a fortnight. That equates to over $400 billion a year.

Our current welfare budget is around $160 billion a year. Not all of this could be saved – a significant chunk is spent on administration. But even with significant savings, a recent report by the Centre for Independent Studies found that the cost to the federal budget would be an additional $230.9 billion a year. Current total Commonwealth tax revenue, ex GST, is around $300 billion – so we’re talking about an increase in tax revenue of more than 75 per cent.

Modelling to cost a UBI is currently underway by Ben Phillips and Miranda Stewart at the ANU, but early findings indicate that, to fund a model as outlined above, a significant increase in personal income tax rates and taxation of the family home would be necessary.

Good luck selling that to the Australian public, Senator Di Natale.

Leaving aside cost, there remain myriad other problems with the concept from a progressive perspective.

Firstly, there is the issue of tax churn: high-income earners would receive a payment only to return it, and more, in increased income tax. Why introduce such complexity into our progressive tax and transfer system, which is one of the most tightly targeted in the world? There are already too many loopholes in our system by which the wealthy minimise their taxable income: creating a UBI would be a massive incentive for them to increase tax avoidance.

Secondly, there’s a reason that conservative thinkers like Charles Murray, and even the father of neoliberalism Milton Friedman, support versions of the UBI: they know it’s a way to reduce the size of government and increase people’s reliance on the market.

By replacing welfare programs with a cash payment, right-wing proponents of a UBI argue that government can stop delivering basic services and simply give people the money to buy social services from private providers.

The hollowing out of the middle-class in the US is a direct result of decades of policies that deny universal services and reduce the size of government in favour of the free market.

A far better solution to inequality is to build on the Australian tradition of providing universal services and increase government provision of health, education and social services, reversing privatisation and for-profit provision of essential services and equalising access.

Thirdly, a UBI robs people of agency. It completely ignores the value of work beyond earning an income. Too often progressive advocates of the UBI fall into the trap of believing, as many conservatives do, that people don’t want to work.

The fact is, work is critical to people’s sense of identity. We are inherently wired to want to create, to contribute, to make something of our lives. Most people want to provide for themselves, rather than rely on support from the state.

I’m yet to meet a proponent of the UBI from a working-class background. It’s the latest pet policy of the post-materialist middle class.

The element of the UBI that most progressive advocates rely on to defend against these criticisms is that, where it has been tried, there is evidence that providing a living income to people who are out of work, or retired, or unable to work because of disability or caring duties, and not requiring them to jump through hoops to get it, allows them to be productive, happy, contributing members of society.

This is, indeed, a compelling argument – but it’s not an argument for a UBI. It’s an argument to stop taking a punitive, stigmatising approach to welfare across the board, and ensure that our targeted tax and transfer system is more fairly and benevolently applied.

So let’s do this, and stop the nonsense about paying money that we can’t afford to everyone.

Emma Dawson is executive director of public policy think tank Per Capita.