Policy-makers and banks must not "try to engineer" a revival in credit growth as an antidote to the slow-down in economic growth that is connected to the decline in mining investment, Glenn Stevens, governor of the Reserve Bank of Australia, advised in a speech yesterday.In the speech, made in Sydney, he reflected on the passing of the "two booms" - in credit and in mining investment. Stevens said: "It would seem unlikely that we could bank on a resumption of sustained growth in assets, in real per person terms, of seven per cent per year over the next few years.""It follows that the saving rate is unlikely, any time soon, to decline back to where it was in 2005. "Average saving rates well above that earlier level seem more likely for some time, even though there will presumably be cyclical ups and downs. "While current saving rates have been described as 'high', a look at longer-run history suggests that 'normal' would be a better description," Stevens said.He said that "implications that might flow" from his observations include that "we should not expect a return to the sort of growth seen in the 1995 to 2007 period. Nor should we try to engineer one, at least on the back of borrowing.""Households continue to service their borrowings well - the household arrears rate is low and has fallen slightly over the past year - but we would be risking future problems were we to see a big run-up in debt from here. "This does not preclude prudent levels of borrowing by new entrants to the housing market, or by investors."But Stevens cautioned that "we are unlikely to see a return to the earlier boom conditions."