Auction clearance rates are going nowhere, still, but one measure of the impact of macroprudential policy in Australia may be ringing true.Large lenders report that the interest-only share of loan approvals has declined to around 30 per cent in the June 2017 quarter, the Reserve Bank of Australia said in its Statement on Monetary Policy on Friday.While "housing credit growth has been stable over recent months," the RBA said, "growth in investor housing credit has declined recently, after accelerating through the second half of 2016," an outcome chased by APRA and the RBA for more than two years."This has been largely offset by slightly faster growth in housing creditextended to owner-occupiers," the RBA said.The recent tightening in lending standards "in response to prudential guidance from APRA and ASIC in March and April may also have had some effect. "This guidance requires lenders to limit the share of interest-only lending tobelow 30 per cent of new loans from September onward. The RBA sounded another note of optimism on regulator activism.?"Investor credit growth has moderated and loan approvals data suggest this will continue in coming months," it said in the SOMP."Also, new interest-only lending has declined recently in response to the higher interest rates now applying to these loans and other actions by the banks to tighten lending standards."Still, the flow though to housing prices and sales turnover in property is as doubtful as ever.??CoreLogic, in a summary of housing auctions for the weekend, reported a preliminary auction clearance rate of 71.5 per cent for the first week of August, up from 68.7 per cent in the last week of July.Over the last month, "auction volumes have remained relatively steady and while clearance rates have shown a softening," CoreLogic said.On the face of it, banks' responses to regulator pressure may aid margins, since funding costs are moving the other way."The cost of the major banks' outstanding deposit and wholesale debt funding is estimated to have declined a little this year," the RBA said."Interest rates on term deposits and savings accounts have declined, and the average cost of term deposits is expected to decline a little further, reflectingthe maturity of deposits that were entered into at higher interest rates last year.