As credit standards continue to tighten in the face of soon-to-be-implemented regulations, potential nonprime borrowers will increasingly find themselves marginalized in the mortgage market, according to Lewis Ranieri, the former Salomon Brothers vice chairman who helped pioneer mortgage-backed securities four decades ago. In a new white paper Ranieri co-authored, he makes the case that mortgages with credit scores below 680 are currently considered subprime, while the subprime cutoff before the ...