1. "I don't think a flat yield curve is sustainable ." 2. "Greenspan thrives on a flat yield curve because it indicates low inflation, " he said. 3. The stage just before that is a flat yield curve, when the spreads narrow toward zero. 4. Continued heavy issuance will depend on a combination of sustained lower long-term rates and a flat yield curve. 5. The sum may not be exact because modified duration assumes a flat yield curve, which is seldom the case. 6. "A flat yield curve keeps prepayments down, " said Steve Abrahams, an analyst at Morgan Stanley, Dean Witter Discover & Co. 7. "A flat yield curve keeps prepayments down, " said Steve Abrahams, an analyst at Morgan Stanley, Dean Witter Discover & AMP; Co. 8. "Interest rates, which rose when the pressures began, fell back substantially, leading to a fairly flat yield curve, " it reported in the study. 9. The Merrill Lynch analyst added that demand for derivatives could fall, and trading inventory could have a higher cost under a flat yield curve. 10. If there's no increase tomorrow, " the short end will be bought some and we'll have a less flat yield curve, " said Nomura's Miyamura.