Having your cake and eating it too: The maturity structure of US debt
How the US Treasury can both lengthen and shorten its debt at the same time, to buy insurance against interest rate rises and provide "liquidity." A short paper diguised as comments on Greenwood, Hanson, and Stein “A Comparative Advantage Approach to Government Debt Maturity†at the Second Annual Roundtable on Treasury Markets and Debt Management, US Treasury, Nov. 15 2012.