Officials testifying before a Senate Banking, Housing and Urban Affairs Committee hearing this week came out in strong opposition to eliminating a government guarantee in the MBS market of the future, claiming that such measures would have a significant impact on borrowers’ ability to obtain plain vanilla 30-year fixed-rate mortgages. “Many large investors utilize the MBS market to execute trades driven by macroeconomic views and would not utilize a market which combines credit risk with interest rate risk,” said Andrew Davidson, president of Andrew Davidson & Co., an analytics and consulting firm. “With a smaller investor base, liquidity would be...