3 6/7  BIS central bankers' speeches  3 Potter, Gradual and Predictable: Reducing the Size of the Federal Reserve’s Balance Sheet, October 11, 2017. 4 See Potter, Implementing Policy with the Balance Sheet, November 6, 2017, for further discussion of lessons  from experience with balance sheet policy. 5 The maturity structure of the balance sheet was only loosely incorporated into the purchase plan. Purchases of  Treasury securities were targeted at maturity sectors; within each sector, specific issues were selected for purchase using a relative-value approach based on a spline fitted to market prices. Sack, Implementing the Federal Reserve’s Asset Purchase Program, February 9, 2011. Treasury securities acquired through reinvestment are purchased in proportion to issuance. Agency MBS purchases are distributed across instruments roughly in proportion to anticipated gross issuance of those securities at the time. Potter, The Implementation of Current Asset Purchases, March 27, 2013. 6 Early FOMC discussions of balance sheet normalization, then referred to as an “exit strategy,” were predicated  on an intention to return to, as put in the January 28, 2009, meeting transcript, “a more normal framework for conducting monetary policy,” which meant a return to an asset and liability structure closely resembling that which prevailed before the financial crisis. Normalization-related matters were discussed in the minutes to most of the FOMC’s 2009 meetings.
Even the Basel II regulations, which will come into force in 2007, provide scope for regarding mortgage bonds covered by legislation on secured bonds as more creditworthy than mortgage bonds not covered by such legislation. However, the Swedish market for mortgage bonds is already a large, liquid market that has functioned well since its deregulation at the end of the 1980s. It is the third-largest mortgage bond market in Europe, after the German and Danish markets. After the Swedish government, Swedish mortgage institutions are the largest issuers in both the money and bond markets in Sweden. As much as around 40 per cent of all lending to the non-bank public is mediated via mortgage institutions, which largely finance their activities by issuing bonds and certificates in the securities markets. The market is dominated by five mortgage institutions, which together account for around 99 per cent of all borrowing. The four largest mortgage institutions are subsidiaries of the four largest Swedish banks, while the fifth, SBAB, is state-owned. The mortgage institutions’ annual reports show that as much as around 30 per cent of securities borrowing is carried out abroad, which suggests that there was already considerable interest among foreign players before the legislation on secured bonds was proposed. However, there are considerable differences between the institutions.