Public Accounts committee  We do a lot of work in the context of budgets, which I can't really talk to. We do look at these issues kind of continually. But I can't tell you whether we've evaluated specifically the threshold and whether we've thought about increasing it.

Public Accounts committee  I guess what I'm saying is when we analyze a measure, when we look at changes in the measure, we look at the risks associated with that, and we provide advice in relation to that.

Public Accounts committee  It's provided to the minister.

Public Accounts committee  That's correct.

Public Accounts committee  I'm not sure.... I mean, the tax system is a collection of those individual measures—

Public Accounts committee  —so we're looking at those individual measures.

Public Accounts committee  Yes.

Public Accounts committee  Yes. We publish the tax expenditure report in line with the tabling of the main estimates every year. In preparation for that, we use the latest available data, which will vary from measure to measure. Whether it's a corporate measure or a GST measure, the data sources are different.

Public Accounts committee  The document referred to was an internal policy development paper that we prepared in looking at evolving the policy. It wasn't a document that we prepared for public release.

Public Accounts committee  As I say, it was prepared for an internal purpose, in terms of the policy development and the changes under consideration at the time.

Public Accounts committee  I think I said that it's part of our analytical framework. We have a kind of template that we use when we look at any tax measure, and part of that is looking at spending alternatives, alternative delivery mechanisms. I think there are exceptions where we don't get much further than looking at it and saying, well, there isn't an exception.

Public Accounts committee  I'm not aware of the specific risks referred to in the report. But I guess what I would say as a general statement before I come back to the specific is that I don't think there is any case where there aren't risks, in my experience, when looking at a tax measure. There are always risks, whether they be compliance risks or risks that the reality will be different than our anticipation of the reaction of taxpayers.

Public Accounts committee  I would suggest that the objective of providing those measures will be to allow a better sense of how the tax expenditure will grow in importance over a few years. I think you can do that in many tax expenditures by looking at the four years of historical data and the two years of projections, but I guess an additional two years would allow you a little more understanding of how they are growing.

Public Accounts committee  I think there's always value in information. As I say, if I sound cautious, it's because we wouldn't want to give a false degree of assurance as to what those expenditures would be in particular cases where there's more volatility expected.

Public Accounts committee  I think I'd respond by saying that when we analyze particular tax measures—and you referred to one and our work on flow-through shares and the mineral exploration tax credit—we apply a whole range of considerations. Firstly, what's the policy objective of the measure? What's the policy gap in that case?