How much is the MRRT earning - Around $414 million a quarter

Lots of controversy in the press regarding the Mineral Resource Rent Tax and how the Tax department can't give out any information to the Treasurer as it would violate Privacy. Pleasseeeeeee.
How a Government Department (even the Taxation department) that isn't indepentent by any means (unlike the Reserve Bank) can deny information from it's head is rubbish in my opinion. So why the secrecy.

Here at Goat central, we like to get to the bottom of things. So I have created an extremely simplistic econometric model to see if I can separate the wheat from the chaff so to speak. The model is as follows

Quarterly Resource Rent tax earnings for the present quarter = constant + A*(Quarterly Resource Rent Earnings for previous quarter) + B*(Dummy Variable of MRRT applied) + C*(CPI for the quarter)+Error

As mentioned, very simplistic, but the Co-efficient of the Dummy Variable should give us a rough estimate of how much the MRRT earns in a quarter. (though as we have figures for only 1 quarter of the MRRT, it is an extremely rough estimate). Be better once we have the next couple of quarters.

I optained the monthly data of earnings from the total RRT (which includes both PRRT and MRRT) from the monthly and annual statements on www.finance.gov.au (to gain quarterly, I added up the earnings from the previous 3 months). CPI data I located from www.abs.gov.au (which is the annual change in the prices from same quarter of previous year). I then loaded it all into excel and performed an OLS regression. Results are

Quarterly Resource Rent Tax earnings = 60.2+0.295*(Quarterly Resource Rent Earnings for previous quarter)+414.63*(Dummy Variable of MRRT applied)+6678.94*(CPI for quarter)
(all co-efficient figures in millions)

Adjusted R2 = 0.21
Error = 158.76

So based on this, the MRRT is earning roughly $414.63 million in it's first quarter. It is statistically significantly different from zero at the 95% confidence interval (this confidence interval is $765 million (max) to $56 million (min)) So even at it's most optimistic, the MRRT is likely to earn only $3 billion a year, and with the PRRT only likely to hit $1.5 billion (5 year average), it's a far cry from the $7.5 billion budgeted by Treasury. It's a $3 billion black hole.

No wonder the Government want to hide the figures.