  At the outbreak of the recent inflation surge, the public's attention to
inflation was low but increased quickly once inflation started to rise. In this
paper, I quantify when and by how much the public's attention to inflation
changes, and derive the macroeconomic implications of these attention changes.
I estimate an attention threshold at an inflation rate of about $4%$, and that
attention doubles when inflation exceeds this threshold. Adverse supply shocks
become more inflationary in times of high attention, and the increase in
people's attention to inflation in 2021 accounts for half of the subsequent
supply-driven inflation. I develop a model accounting for the attention
threshold and show that shocks that are usually short lived lead to a
persistent surge in inflation if they induce an increase in people's attention.
The attention threshold further lengthens the last mile of disinflation after
an inflation surge, and leads to an asymmetry in the dynamics of inflation.
