I reckon I’m like most people. Quick to think something’s a good idea but, if it means me forking out some of my own money, then the old enthusiasm can wane a bit.

And that’s exactly how I’m feeling about the Green Party’s tax policy. I’ll tell you why shortly.

But first, you will have heard and seen that there’s already been the usual whingeing about their idea of a wealth tax. The wealth tax critics always crack me up because they trot out the same old lines about wealth taxes being a bad thing because they stop people aspiring to better themselves.

Which is such a load of nonsense because, you ask anyone who’s made a real success of something - for example, they might’ve invented an amazing new product or they might be an amazing artist or musician - and nine-times-out-of 10 they’ll tell you that making money was never in their mind when they started out.

Do you really think Ed Sheeran, for example, picked up a guitar because he wanted to be a millionaire? Of course not! Do you really think Sir Ian Taylor, who started Animation Research in Dunedin years ago and is doing all sorts of incredible stuff with live sports broadcasting, do you think his number one motivation was making a truckload of money? Of course it wasn’t. So anyone who says wealth taxes stop people from striving or having aspirations doesn’t know what they’re talking about.

But the aspect of the Green party’s tax policy that's got my attention is this idea of a Minimum Income Guarantee.

The basic idea is that everyone would be guaranteed to get paid at least $385 per week. Individuals would be paid at least $385 per week. Couples would be paid at least $770 per week. And single parents would get at least $735 per week.

The Greens think this is the way of ending poverty in New Zealand.

As I said earlier, this is one of those things that I want to like. Because who is going to argue against the obvious benefits of making sure every adult in the country has something coming in the door each week?

But it’s also one of those ideas where I find my enthusiasm waning a bit because it means I have to have some skin in the game. By paying more tax.

The Greens are making the bold claim that their plan would see 95 percent of us paying less tax. It’s a line some media outlets have been trotting out but, when I look more closely at what they’re proposing, I wouldn't bet the house on it.

Because the only reduction I can see - other than the zero tax on revenue under $10,000 per annum - is where someone earns between $10,000 and $50,000. Currently, the maximum rate people in that bracket pay is 17.5 percent. The Greens would reduce it to 17 percent. So, marginally better-off.

Elsewhere, if you earn over $75,000, the Greens want your top tax rate to be 35 percent. At the moment it's 33 percent.

If you earn over $120,000, your top tax rate will be 39 percent. At the moment it's 33 percent.

If you earn over $180,000, your top tax rate will be 45 percent. At the moment it's 39 percent.

So I reckon that, despite what the Greens are saying, most of us would actually end up paying more income tax if this Minimum Income Guarantee was going to be even remotely possible.

And I’m afraid that even my good heart is stopping me from giving a ringing endorsement to this idea.

Yes, I think a Minimum Income Guarantee would be brilliant. But I think the Greens have gone off half-cocked. Because I’m not convinced they’ve done the numbers properly. I’m not convinced that a wealth tax and tinkering with current income tax rates would make the scheme sustainable.

Most significantly, though, I don’t believe the Greens when they tell me that I wouldn’t have to pay more tax to make it happen.  

I like their idea. But I don’t like it enough to pay more tax.

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