There's been a lot of attention paid to Australian house prices and affordability in recent days. (When hasn't there been in the last 20 years?) Looking at the latest Rismark housing affordability measure, CommSec analysts have concluded that home prices stood at four times household disposable income in the December quarter - a figure broadly unchanged from a decade ago. Over the past decade disposable income per household has risen around 70 per cent while the average home price has lifted around 67 per cent."This means Australians have got richer over time," said Craig James, chief economist at CommSec.According to James, while Australian homes are less affordable than 20 years ago, that's not because income growth has been sluggish. He says it's because wealthier Australians, taking advantage of lower interest rates and "more affordable basic necessities", have channelled extra dollars into the family home. "Homes are bigger and of higher quality than 20 years ago," James said. He noted that the latest data supports the Reserve Bank's view that recent increases in home prices are not of undue concern.This view was echoed by NAB's credit analysts in a note to clients yesterday, drawing on a Moody's Analytics stress test of Australia's housing market. Moody's used three measures of affordability: the price-to-income ratio, the price-to-rent ratio and the share of income required for mortgage payments for their test.Applying a series of domestic and external shocks to their model, Moody's created scenarios where house prices could fall by up to 30 per cent under a global recession, "but in reality the base case is for further price appreciation," said NAB.They concluded that for Australia as a whole, house prices are currently near fair value, but with plenty of variation among the states. "House prices in Victoria are slightly overvalued and particularly vulnerable to adverse shocks. South Australia and Western Australia, by contrast, appear undervalued currently," they wrote. Nevertheless, WA remains "highly exposed to a downturn in the global economy and a fall in commodity prices."House prices in NSW, Queensland, the ACT, Tasmania and the Northern Territory appear close to fair value according to this analysis.