Abstract. The article examines macroeconomic policy options for advanced economies to respond to adverse shocks in the environment of very low interest rates and very high levels of public debt, when the scope for using conventional policy tools is limited. The standard transmission mechanism of monetary policy in the ELB conditions stops working normally, and the economy faces the “liquidity trap” effect. The deployment by central banks of unconventional monetary tools (forward guidance, quantitative easing, and negative interest rates) after global financial crisis was helpful in combatting the downturn, but carries risk of possible side effects. Large-scale purchases of financial assets lead to significant increase in central banks’ balance sheets, and this creates a threat to future financial stability and central bank independence. Negative interest rates can have detrimental effects on bank profitability and be contractionary through bank lending. There is a consensus that today fiscal policy has to play a major role in stabilizing the business cycle. But the effectiveness of conventional tools of discretional fiscal policy is uncertain because of long political lags and small spending multiplier. Existing automatic fiscal stabilizers are focused on social protection goals and not on macroeconomic stabilization. Thus, the newly proposed measures for rules-based fiscal stimulus (asymmetric semiautomatic stabilizers – tax or spending measures triggered by the crossing of some statistical threshold, e.g. a high unemployment rate) and unconventional fiscal policy (the use of consumption taxes to increase inflation expectations) have become the object of active discussion. Here lies the danger in the fusion of monetary and fiscal policy: central banks’ operations are becoming increasingly quasi-fiscal, aimed at financing budget deficit, and functions of monetary policy are proposed to assign to fiscal policy. Besides, the expansion of fiscal stimulus threatens financial stability in the future, as it leads to increase in public debt and narrows a country’s fiscal space.