New global standards for writing mortgages will add international weight to the Australian Prudential Regulation Authority's supervision of the Australian mortgage market.The new standards were foreshadowed at the end of last week by the Financial Stability Board, the peak international body for banking regulators. The FSB released a "peer review" on mortgage underwriting and origination practices - a document comparing residential mortgage underwriting and origination practices across the FSB's membership.In arguing for a focus on mortgage underwriting and origination practices, the review suggests that the collapse of US residential lending standards caused the 2008 global financial crisis.And, it says, FSB members should follow six recommendations "to promote sound residential mortgage underwriting practices". One of those recommendations is that the FSB itself should create "an international principles-based framework for sound underwriting practices".The Reserve Bank of Australia's Luci Ellis was one of eight global regulatory figures who drafted the review, and none of its recommendations appear to go beyond prudential measures already put in place by APRA and the RBA.These recommendations also include developing "a framework for sound residential mortgage underwriting standards" - which, in Australia's case, probably describes APRA's existing prudential framework, including its published prudential practice guides.The FSB recommends that financial authorities review and adjust their standards on residential mortgage underwriting "to address the build-up of risks in the housing market or to help counteract a lending boom that poses significant risks to financial stability". APRA's leadership has clearly signalled in recent statements that they favour the activist supervision implied in the FSB recommendation.The FSB standards may help APRA to defend itself against future charges of overly intrusive supervision. APRA's recent statements, most notably a speech by policy and research head Charles Littrell, have shown APRA is worried it may at some point lose political support for aggressive supervision.The FSB peer review also underlines continuing sharp differences in both banking prudential regulation, and banking industry practices among the advanced economies.In particular, the review shows sharp differences between most advanced economies and the US - the market "where lending standards eased the most" in the lead-up to the 2008 crisis.The review delicately avoids naming the US when noting that the crisis showed how "the consequences of weak underwriting practices in one country can be transferred globally through securitisation of mortgages underwritten to weak standards".