step,rule,n_before,n_after,n_removed,rationale
1,GDP month <= t-2 at last origin 2026-04 (publication lag); drops 2026-03..2026-09,345,338,7,information-availability rule
2,target month needs gdp_yoy(m-3) and emp_yoy(m-2) inside the file,338,335,3,lags unavailable for first months of file
3,drop pairs with target/regressor month in 2020-03..2021-12,335,310,25,pre-specified COVID outlier exclusion (model only)