Since the Covid pandemic struck in the US in 2020M02, 1.1 percentage points; since 2021M03, 1.6 percentage points, using HICPs (0.4 ppts and 0.7 ppts, respectively using CPI for US, HICP for Euro Area).
Figure 1: Month-on-month annualized inflation differential for US-Euro Area (black), calculated using log differences. HICPs seasonally adjusted by author using geometric Census X-12. NBER defined peak-to-trough recession dates shaded gray. Source: BLS, Eurostat via FRED, NBER, and author’s calculations.
Given the variability in m/m inflation, it’s not surprising that in no case is the measured acceleration statistically significant.