1step,rule,n_before,n_after,n_removed,rationale2UNRATE_1,drop months with blank UNRATE,945,944,1,2025-10 value blank in FRED file; outside sample3UNRATE_2,keep months 1959-10..2019-12,944,723,221,levels needed for 1960Q1-2019Q4 differences; post-2019 excluded by rule4UNRATE_3,average 3 months -> quarters,723,241,482,u_t = mean of 3 monthly values (rows are now quarters)5GDPC1_1,keep quarters 1959Q4..2019Q4,319,241,78,levels needed for 1960Q1-2019Q4 growth; post-2019 excluded by rule6MERGED_1,first difference (drop 1959Q4),241,240,1,1959Q4 only provides lagged levels7