But they would be consistent, though only just, with what the Reserve Bank said in its regulatory impact assessment of the LVR curbs, released on Tuesday: "Approximately 12 per cent of banks' new lending is to high-LVR first home buyers."
The bank goes on to suggest that first home buyers unable to borrow while the LVR restrictions are in place "might gain from being temporarily shut out of the market", for example, if house prices fall or if future mortgage rates would have placed them under financial distress.
The Reserve Bank said its modelling suggested that as a result of the curbs, house price inflation could be 1 to 4 percentage points lower over the first year than it would otherwise be, and credit growth would be reduced by between 1 and 3 percentage points.
It has cited the need to boost the shock-resistance of the banking system as its primary reason for introducing the LVR curbs and said the measures would be temporary, without indicating how it would decide when to lift them.
But restrictions on the flow of new mortgage lending would take time to materially strengthen banks' balance sheets.
"The impact of LVR restrictions on banks' resilience in a downturn would depend crucially on how long restrictions had been in place prior to the downturn," the impact statement said.
"The Reserve Bank's analysis ... suggests if the proposed LVR restriction was in place for two years prior to a severe housing market downturn, it would reduce losses on residential mortgage loans by 10 to 15 per cent."