Last week's co-ordinated cuts in five-year home loan pricing are a reminder of an industry searching for volume and cutting margins to attract it.Followers have to follow - and both Citi and AMP did yesterday, amongst others publicising changes.Brand new home loan business is the point of this style of pricing - flushing out new-to-market leads, expanding the market and building volume.Volume is something the industry clearly prefers. In the past banks have mainly handled the volume growth story - in home loans, at least - pretty well.Mad exceptions recur (on the Queensland gold coast mainly) but on the whole periods of severe home loans losses have been localised and limited.The obvious attractive driver of credit expansion in Australia is home loans and the industry must be sorely tempted to dial up on risk and go for growth.The whole banking industry in union may thus be a great driver of economic growth, complementing the remainder of the minerals boom.Big banks, leading the push, start with a market share of nearly 80 per cent.They let that share slip to as low as 59 per cent during the last credit boom, meaning there is a lot of market share to attack during a growth phase for ambitious loan market challengers.These forces may well already be combining to coax home loan credit growth into life.