Both Phillips curves were drawn based on two observation periods: (1) from 1998 Q1 to 2012 Q3 (from the period with a decline in wages to the period prior to the sharp depreciation of the yen and stock price hike); and (2) from 2012 Q4 to 2014 Q1 (from the period of the sharp depreciation of the yen and stock price hike to the present).
BIS central bankers’ speeches  7  For some years there had been evidence of a slowing in productivity growth, beyond the unusual factors clearly at work in a couple of sectors (mining and utilities). The most recent data on productivity show signs of a pick-up in the year 2011/12, which is encouraging (Graph 5).