There is no consensus in the literature on the optimal use of macroprudential policy to ‘lean against’ financial vulnerabilities. This column introduces a new empirical approach to study the effects of both macroprudential and monetary policies in response to looser financial conditions. It finds that tighter macroprudential policies can be very effective in mitigating emerging vulnerabilities, mainly by reducing the future volatility of output. In addition, such tightening is best accompanied by looser, not tighter, monetary policy.