This analytical problem has been further complicated in the current episode by unexpectedly weak productivity growth earlier in the expansion. Recent data 1  BIS Review 94/1999  are consistent with an increase in the productivity trend, but given that the evidence for an upturn in the productivity trend is so recent, considerable uncertainty remains about what the underlying trend will be going forward.
Many forecasters, myself included, have been revising upward their estimate of trend productivity growth in response to recent unexpectedly strong productivity growth. Many of these estimates are now about 2% or slightly higher. Part of the increase – about ¼ percentage point – from the earlier trend of just above 1% reflects improved measurement and is not in fact an acceleration of true productivity.