I rather hope that the Dominion Post, a New Zealand paper that's not featured here before, will forgive me borrowing the following editorial, but I did the research on which it is based so I hope there's a quid pro quo in this:

There is nothing wrong with tradespeople and other small businesses offering discounts in return for cash payments, provided they are doing so to make life easier for themselves and their customers. There is, however, something very wrong with them systematically discounting work for cash so they can hide the true amount they earn and avoid paying their full share of tax.

New Zealand has a long history of cash jobs, and reducing prices for cash payments can make good business sense. Unlike cheques, credit cards and bank transfers, cash costs nothing to process and the money is immediately available to pay suppliers or other bills — an important factor for single and small operators when times are tough, as they are now.

There is a big difference between that, however, and the level of systemic rip-offs uncovered by the international Tax Justice Network's research into New Zealand. It found a shadow economy worth an estimated $20 billion a year, the equivalent of one-eighth of the country's total annual economic output. According to its figures, the lost revenue from this hidden market is in the region of $7b a year, most of it thought to be due to tradespeople who do not declare their true earnings.

The huge sums involved should give pause to those who would not normally hesitate to agree to paying cash for heavily discounted prices in the knowledge — or at least the very real suspicion — that the reason is so the person doing the work, offering the service or making the sale can cheat on their taxes.

Just as taxpayers rightly condemn beneficiaries who commit welfare fraud, big corporations that try to get out of paying the tax they owe and others who arrange their affairs to pay less than they should, so, too, they should condemn tradespeople and small businesses who are also ripping off the system.

New Zealanders need only look to the example of Greece to see what happens when large-scale tax cheating occurs. While the level of tax avoidance here is nowhere near as bad as that which has effectively bankrupted Greece, mainly due to much more robust income tax systems, the $7b lost through the shadow economy is significant.

It is enough to fund almost half the cost of the public health system, or the full cost of all the Roads of National Significance presently under consideration. Put another way, it is the same amount this Government hopes to raise from the partial sale of state-owned energy companies and its stake in Air New Zealand.

Cracking down on those who engage in under-the-table dealing on a regular basis is not easy. They are often hard to detect, and the ingrained nature of the mates' rates, cash jobs and payments-in-kind culture only makes the task all the more difficult.

The Inland Revenue Department has been given extra funding to go after tax cheats, however, and is signalling that tradespeople and small businesses operating under the radar will be high on the list. So they should. They are in effect stealing from all taxpayers, and should be targeted with the same zeal as others who are ripping off the system.

First the logic of this impeccable.

Second, it's great to see the comparison: New Zealand sells off major state assets that might provide a continuing income or can tackle tax evasion to achieve the goal. Put like that the choice is pretyy obvious, isn't it.

So why isn't more being invested in tackling tax abuse?