After years of strong growth, housing prices have been declining nationally, led downwards by falls in Melbourne and Sydney over the past year, along with a decline in investor credit growth and an easing in owner-occupier credit growth. These are among well documented measures implemented by regulators - notably the Australian Prudential Regulation Authority between 2014 and 2017 - to address the risks of an overheated housing market also led to a noticeable slowing of investor credit.This was the starting point for Christopher Kent, the Reserve Bank of Australia's assistant governor for Financial Markets, in a keynote address to the Australian Securitisation Forum ConferenceHe then noted a "story less often told about the important causal link going in the other direction" - the correction in the housing market over the past year or so appears to have been impinging on the demand for credit due to: •    the majority of borrowers have chosen to borrow much less than the maximum amounts offered by lenders; and•    given that owner-occupiers have lower incomes on average than investors, they are likely to have seen noticeable reductions in maximum loan sizes as a result of the recent tightening in serviceability practices. However, owner-occupier credit growth has remained notably higher than investor credit growth, which has had flow-on effects to the RMBS market. In 2018 RMBS issuance in aggregate has been lower than in 2017, largely due to decreased issuance by banks. Non-banks, by way of contrast, are continuing to issue close to A$4 billion of RMBS per quarter, a situation that Kent said "is consistent with a sizeable increase in their mortgage lending … [as a] consequence of the tighter supervision and regulation of mortgage lending by banks.""The increase in the share of investor housing in deals issued by non-banks is one of the few noticeable changes in the composition of the collateral underpinning RMBS in the past couple of years," Kent said.One of the other changes to loan pools in new deals is a fall in seasoning (ie, the age of loans when the deal is launched). "This has been most pronounced for non-banks. It is consistent with non-banks writing a lot more loans," Kent said. "Hence, warehouses of their loans are reaching desired issuance sizes more quickly."Despite the pull-back in RMBS issuance by the major banks over recent years, the broader stock of asset-backed securities on issue increased by around $20 billion over the past 18 months, after remaining broadly stable for the previous five years. An increase in bank bill swap (BBSW) rates in early 2018 has led to a modest rise in the funding costs of both banks and non-banks. However, the increase in overall funding costs has been a bit greater for non-bank issuers than for banks, which have a sizeable proportion of their liabilities - such as retail deposits - that do not reprice in line with BBSW rates. Kent's final piece of analysis led him to remind RMBS issuers and investors to consider the implications of developments