The results show that if the central bank grants loans against non-marketable low-quality collateral, this can improve the functioning of the repo market as more high-quality collateral becomes available for private market transactions. When collateral had become scarce as a result of the Eurosystem’s extensive asset purchase programmes, banks benefiting from a looser collateral framework submitted non-marketable credit claims as eligible assets and lent marketable government bonds in the repo market. The expansion in the bond supply, especially the increased re-use of additional bonds in several transactions, together with other Eurosystem measures, ultimately led to a reduction in scarcity premia and thus to a decline in asset scarcity. However, whether and to what extent such a measure could be a meaningful addition to the monetary policy toolkit requires an overall assessment that would cover, for example, additional balance sheet risks, alternative measures and incentives set for banks, and this goes beyond the scope of this analysis.