Households real income and housing costs

Comments on Christopher Joye "The house that pocket change built", 17/08/2011, http://www.businessspectator.com.au/bs.nsf/Article/RBA-house-prices-mortgage-rates-disposable-income-pd20110816-KS3L5?OpenDocument&src=rot

It is an interesting article and useful information.
However, could the auther do some further anlaysis, removing some of the changing factors like the increase in 'empoyment' per household, and possibly a scenario of adjusting for interest rate change to see a case if interest rate moves higher?

Doing those would provide a more comparable comparison and is likely to singificantly qualify the conclusion the author derived. It would also provide some sensitivity analysis for affordaility when interest rate moves unexpectedly.