Federal Reserve officials are keen to start debating their balance sheet run-down endgame, but benign market conditions, recent central banker comments and bond dealer estimates now suggest the process may run longer than previously thought. One factor driving the rethink is a puzzling bout of better-than-expected liquidity conditions in U.S. short-term financing markets that has for now at least forestalled a run of volatility that some on Wall Street had expected to force the Fed's hand into stopping the balance sheet shrinkage effort known as quantitative tightening. On top of that, minutes of the Fed's most recent meeting in January showed some policymakers interested in an extended slowdown in the pace of shrinkage - a tapering - that could actually allow QT to proceed for a longer period.