The application of thresholds is useful to discuss, but I keep looking for the information on the accuracy of the test used i.e. the sensitivity and specificity (and from what of evaluation that information was derived). From that information - essentially the rates of true positives and true negatives - the rates for false positives and false negatives can be derived and thence likelihood ratios (LR) for the test being accurate (+) or inaccurate (-) if a house is actually contaminated (at whatever level). A useful diagnostic hermeneutic is in clinical practice is a test is valuable if the LR+ is 10 or more and/or the LR- is 0.1 of less.

I like it - I have been buying only NZ literature for the past 15 years (reading diet more extensive of course) and would actively support such an option. Strangely that is what I thought I was doing by using the local bookshop and that does point to the downside - the impact for the independent local booksellers. But with a focus just on NZ books, well booksellers could survive on a non-NZ diet perhaps. David Beattie's book blog gets something like 1500-2000 hits in a day - the blog-side could possibly include more than just authors?

While clearly KiwiSaver is targeting new savers, the issue of most interest to me, as one already contributing 4% of income to a private locked in retirement plan, is what action would most benefit those in my position?

I could just hope that the private plan sees sense and tries to become KiwiSaver compliant, but that will be a very slow train coming. So the remaining options would seem to be:

1. Continue contributing to the private plan and take advantage of the government and employer contributions by joining KiwiSaver. Best option, but very dependent on disposable income levels.

2. To stop contributing to the private plan and start a KiwiSaver plan. Seems like a risky strategy until KiwiSaver is really bedded in (and the National Party makes some policy). Additionally no-one appears to be working the numbers to show how long it would take for KiwiSaver would overtake what could be earnt from the nestegg already in the private plan.

3.To ignore KiwiSaver altogether and lose the possible advantages of third party contributions.

Anybody given any thought to the above?