Most of us underestimate what we spend, but not by much. For every $100 we say we spend on transport, we actually spend $104, according to the Productivity Commission, which compared Bureau of Statistics household surveys with reliable industry data. For rent and communications, that rises to $111. For clothing and homeware, we actually spend about $132. For alcohol, $158.

But for gambling, if we say we have spent $100, on average we have really spent $735. Then there are the pokies. On average, if pokie players say they have spent $100, they have actually spent $3448. That's not a misprint: they are apparently aware of just 2.9 per cent of what they are losing.

Taxes are not the answer to containing gambling. Credit:Nic Walker

Poker machines are not just another form of recreation. Last year's report on gambling by the commission paints a clear picture of the damage pokies do. About 10 per cent of Australian adults gamble regularly (excluding sharemarket speculation). Of that 10 per cent, between 5 and 10 per cent are problem gamblers - that's about 120,000 people. A further 230,000 to 350,000 are taking risks that make them vulnerable to problem gambling.

The clubs industry's campaign against restrictions on poker machines says pokie players who are problem gamblers are a tiny minority. This does not stack up against the commission's figures. Pokie players make up 40 per cent of Australian gamblers, but deliver 55 per cent of gambling revenue, and account for 80 per cent of problem gamblers. These 95,000 people account for 41 per cent of the $10.45 billion in pokie revenue. That's $4.3 billion a year, or an astounding $45,100 each.