Another side effect of the ubiquity of the monoline guarantee is that the investment management community has not developed a standard benchmark for measuring the performance of fund managers investing in PPP and other public infrastructure debt. Because of the triple-A rating of the monolines, managers tended to benchmark their performance against other triple-A securities, with the result that some funds classify these bonds with sovereign debt, others with the triple-A tranches of residential mortgage-backed securitisations, and others with high-grade corporate debt. This seemingly esoteric phenomenon is critical because without a standard benchmark against which investors can judge the performance of individual fund managers, they will be reluctant to commit capital.