Demand factors "have been the more dominant influence" dragging down growth in mortgage finance over the last year, the Reserve Bank of Australia argued in its latest Statement on Monetary Policy.The average outstanding variable interest rate on housing loans has declined moderately since last year, it said, while rates on investor housing credit have tended to decline by more than for owner-occupier credit, "which is consistent with a notable decline in the growth of demand for investor credit.""In addition, growth in lending by non-major banks and non-ADIs has been well above that of the major banks, providing additional credit supply. "Liaison indicates that non-ADIs have been lending to some borrowers who typically would have borrowed from ADIs in the absence of the regulatory measures. This includes interest only borrowers and borrowers who are having difficulty meeting banks' tighter lending criteria."Nevertheless, lending by these institutions remains small as a share of loan approvals and housing credit, at less than five per cent.In a rebuttal to the widely held view that borrowers reaching the end of their interest-only periods are in for a spot of bother, the RBA argued "the available evidence suggests that there has been little sign of widespread financial distress among those who have had their IO periods expire and have started making principal repayments."The RBA provided little support for the guesswork that major banks must soon lift variable rate helm loans as a number of small and mid-sized lenders have done since late June."The overall increase in funding costs [over the last quarter] is significantly less than the 20 basis point increase in BBSW rates," it said.Meanwhile the Reserve Bank its doing its bit for low wages growth, a macroeconomic outcome whose merits its governor, Philip Lowe, has questioned this year."Wage outcomes from enterprise bargaining agreements are likely to remain a drag on overall wages growth," the RBA said in the SOMP. One enterprise bargaining agreement the RBA seems determined fits this bill applies to its own workforce.Workers at Note Printing Australia, a subsidiary of the RBA, were locked out from the banknote and passport printing factory in Craigieburn on Friday. This follows a first ever one day strike by NPA's workforce in May.The printers and supervisors at NPA have been offered a two per cent pay rise, the Australian Manufacturing Workers' Union said.Paid domestic violence leave is another claim resisted, so far, by the RBA, the AMWU said.