The monetary policy stimulus to the Australian economy may be packing a swift, if not yet a decisive, punch.In speech to the Australian Business Economists in Sydney last night Glenn Stevens, the governor of the Reserve Bank of Australia, highlighted the significance and timeliness of the changed stance in monetary policy as part of the response to what he called the international financial turmoil and everybody else seems to have taken to calling the GFC. Stevens said that, using "some fairly elementary calculations", the fall in the household sector's gross debt-servicing burden will be almost three per cent of household income, taking into account the fall in interest rates already pushed through over recent months.This decline in the household debt burden, Steven noted, was "roughly equal to that seen in the early 1990s, when the cash rate fell from 18 per cent to 4.75 per cent. "But on that occasion it took two and a half years; this time it will take place over about four or five months."He noted that the decline in borrowing costs for businesses "has generally been smaller and slower to appear, but there has been some faster pass-through of the most recent reduction in the cash rate."So perhaps in answer to the increasing chatter about the likelihood, and perils, of a "liquidity trap" (at least in other economies with much lower interest rates, such as the US), Stevens argued that "these transmission channels of monetary policy are still operating in Australia."Stevens also put in a plug, in the Australian context, for "other supportive factors" around the financial system, including the fact that Australian banks "do not appear to have had much trouble raising capital from private markets when they wanted it", a point borne out by the smooth capital raisings by NAB last month and Westpac yesterday.