step,rule,n_before,n_after,n_removed,rationale
1,drop exact duplicate rows (all columns identical),445,400,45,file assembled from overlapping extracts; identical rows are the same firm repeated
2,check for remaining duplicate firm_id with conflicting values,400,400,0,none found; one row per firm
3,convert revenue to millions USD (USD_thousands / 1000),400,400,0,"60 unique firms reported revenue in thousands of USD; recoded, no rows removed"
4,exclude firms with unknown (empty) revenue,400,394,6,revenue unknown; cannot contribute to revenue aggregates. Firms: F0048;F0121;F0129;F0269;F0348;F0399