One line leaps out at me from the tax report published on Wednesday. It says the top 10 per cent of income earners now pay 44 per cent of all personal income tax. Think about that.

Nearly half of all personal tax revenue is contributed by just 10 per cent of us. Is this socially healthy? Progressive taxation is a fine principle but its ardent proponents seldom calculate the disproportionality of contributions to the common good.

Healthy or not, our dependence on 10 per cent of earners should be noted every time a "progressive" politician complains that tax cuts favour the rich, or the media highlights the disparities in dollars returned to different income levels.

Read a few lines further into the Tax Working Group's report and the picture gets worse. Once you distribute family tax credits, welfare benefits and national superannuation those top 10 per cent of taxpayers have provided 76 per cent of what is left for general public services. Seventy six per cent.

The Working for Families refund alone results in 40 per cent of households effectively paying no income tax. It would be cheaper not to tax their wages at all. The dependency ratio is not quite as bad as this of course because everyone pays GST at the same rate. Progressive taxers hate GST for precisely that reason.

We will hear from them if the Government adopts the working group's suggestion to raise the rate.

At present GST provides about a fifth of the state's total revenue, personal incomes provide just over half of it. The working group wants to change the ratio a little.

It is not so much concerned about social dependence as the economy's reliance on the taxation of mobile individuals and companies. It advocates shifting more of the load to consumption and property which cannot emigrate.

But it advocates property taxes for reasons of fairness too. If it strikes you as unhealthy that just 10 per cent of the population provides three quarters of the country's net personal taxation, read a little further into the report.

Those 10 per cent are not the richest people in the land, or not all of them. When Inland Revenue did a sample of 100 of the wealthiest individuals in New Zealand it found that only half of them were paying the top tax rate.

The other half may be holding their wealth in a company, a trust or a portfolio investment entity (pie) which are all taxed well below the top income rate. Or they may have invested in property at a tax-deductible loss for a tax-free capital gain.

This country, the group notes, has $200 billion invested in rental property (four times the value of stocks on the NZSE), and the sector as a whole not only contributes nothing to taxation, it reduces the revenue by $500 million a year in rental write-offs.

Right now the bulk of those making a highly disproportionate contribution to the cost of everyone's public services are probably people in salaried employment who lack either the opportunities or inclination to avoid tax.

The survey of the richest 100 was the only element of the report which drew a remark from Bill English on Wednesday. Maybe the trusts, pies and rental deductions will be tackled in this year's Budget if nothing else. Some commentary on the working group report this week has thought it politically too hard to raise GST. I don't see why this should be. Maybe the commentators are unduly mindful of Australia's agony over it. This country took GST in its stride much earlier.

When the initial 10 per cent rate was raised to 12.5 there was not a whimper. I doubt another 2.5 points would faze us.

Curiously, our aversion is to capital gains tax which Australians take for granted.

The working group do not take refuge in the old canard that realised capital gains are somehow not income.

It says, "People earning their income by salary and wage payments should be able to expect they will be treated in a similar way to someone who earns the same level of income from property investment. This is not the case in New Zealand."

But then something strange happens, something that always happens to tax reformers in this country. A clear and simple report turns needlessly complicated and mysterious.

It resorts to jargon about "lock-in effects", "ring-fencing of capital losses" and "boundary problems" that it admits are not peculiar to a capital gains tax.

The group settles instead for a low land tax, an end to depreciation allowances for buildings that are plainly appreciating, and maybe a tax on the assumed rental value of investment homes.

It is not exactly a daring recipe for fairness between taxpayers and better investment in a productive economy.