Inflation Shock Momentum Index (ISMI)

Lansing and Shapiro (2026) | Working Paper

The Inflation Shock Momentum Index (ISMI) measures the share of PCE categories experiencing consecutive months of positive inflation shocks minus the share experiencing consecutive negative shocks. The index provides a real-time measure of inflation momentum across different product categories. You can view ISMI for headline PCE, core PCE, goods, non-housing services, housing, and core goods.

Chart Options

Series to Display

Note: The baseline specification in the paper uses Headline PCE with AR(1) and k=3 (3 consecutive months).

Inflation Series

AR Model

Run Length (k)

Show YoY PCE Inflation

Compare with second series

Current ISMI

Positive Momentum

Negative Momentum

Inflation Shock Momentum Index (ISMI)

Date Range

1969-01

2026-06

Start Date

End Date