For recent programs, this maturity distribution has been announced at the outset, and a schedule of upcoming operations is released at the end of each month.17 Such transparency is possible because, unlike the agency MBS market, the composition of Treasury coupon securities available for purchase is reasonably predictable. The current monthly pace of Treasury purchases is within the range seen during the Federal Reserve’s previous asset purchase programs, whether measured in par terms or when adjusted for duration risk. Current SOMA holdings are less than 20 percent of coupon Treasuries outstanding, and our purchases make up only about 25 percent of monthly gross  14  For example, in January, the Desk decreased its purchases of 30-year fixed-rate 3.5 percent coupon agency MBS relative to projected gross issuance as a result of concerns about the near-term availability of this coupon for settlement and increased its purchases of 3 percent coupon agency MBS. 15  The Desk could also purchase from the stock of securities that trade as specialized pools, although such purchases may involve different efficacy and cost considerations. 16  For example, the percentage of securities issued outside of the TBA market has recently been higher due to programs like the Home Affordable Refinance Program (HARP). MBS backed by loans refinanced through HARP have lower prepayment risk than other MBS, because borrowers can only use the program once, and consequently are not typically issued in the TBA market.

22  See TMPG Best Practices for Treasury, Agency Debt, and Agency Mortgage-Backed Securities Markets. 23  Selling dollar rolls when concerns arise about the availability of certain TBA contracts is conceptually similar to making SOMA Treasury holdings available to the market through our securities lending program. One key difference is that the Desk offers settled Treasury holdings to the market through its securities lending program, whereas the Desk only rolls unsettled MBS holdings. 8  BIS central bankers’ speeches  Fuster, Andreas, Laurie Goodman, David Lucca, Laurel Madar, Linsey Molloy, and Paul Willen. 2012. “The Rising Gap Between Primary and Secondary Mortgage Rates.” Paper presented at the The Spread between Primary and Secondary Mortgage Rates: Recent Trends and Prospects conference, held at the Federal Reserve Bank of New York, December 3. Gagnon, Joseph, Matthew Raskin, Julie Remache, and Brian Sack. 2010. “Large-Scale Asset Purchases by the Federal Reserve: Did They Work?“ Federal Reserve Bank of New York Staff Reports, no. 441, March. Hancock, Diana, and Wayne Passmore. 2011. “Did the Federal Reserve’s MBS Purchase Program Lower Mortgage Rates?“ Journal of Monetary Economics, Vol. 58 (July): 498–514. Krishnamurthy, Arvind, and Annette Vissing-Jorgensen. 2011. “The Effects of Quantitative Easing on Interest Rates: Channels and Implications for Policy.“ Brookings Papers on Economic Activity, no. 2: 215–65. Li, Canlin, and Min Wei. 2012. “Term Structure Modelling with Supply Factors and the Federal Reserve’s Large Scale Asset Purchase Programs.“ Finance and Economics Discussion Series 2012–37. Washington: Board of Governors of the Federal Reserve System, May. Rich, Robert and Joseph Tracy.