the US central bank's dual mandate is not universal, most central banks care about price stability and most central banks are small and most currencies/economi

the US central bank's dual mandate is not universal, most central banks care about price stability and most central banks are small and most currencies/economies are a lot more vulnerable to exchange rate changes. because when an economic downturn starts in export oriented smaller economies the following happens. the reversal of a lot of capital/money flows (investment projects put on hold, sovereign and corporate bond market slows/halts), and then as a consequence of this exchange rate drops (the currency of the smaller economy depreciates) ... and at the same time, basically as the other side of this is that everyone buys US assets (reverse flow!), which pushes up the price of the dollar, which is an extra problem for developing economies, makes raising new debt a big problem (servicing rollover debt is a must at least, and developing economies want to outgrow their debt, so they have a high debt load usually), makes everything instantly more expensive. central banks act as dampers, and there are a bunch of papers about profitability of them, and they detail that by them buying assets when they are undervalued and selling when they are overvalued is their way to dampen these swings and make a profit. which in some cases gets sent to the government budget (eg. in case of Mexico). so yes, while there are asset bubbles that are a consequence of low interest rates, they are not the purpose, nor they are the main consequence of low interest rates, the main effect is economic growth, which helps to lower unemployment, and to avoid recessions (which easily leads to an unemployment spiral).