Is this a mistake or a deliberate choice? (If the latter, why does it differ for OINCWAGE and OINCBUS which both have a quality and a top code flag?)
INCLONGJ (Earnings from longest job) and OINCFARM (Earnings from other work including farm self-employment earnings) are components of INCFARM (Farm Income). While there is a topcode flag for INCLONGJ (TINCLONGJ), we do not currently have a topcode flag for OINCFARM (though this information is available through the source variable UH_TPCDFR1_A1). The topcode flag variable TINCFARM contains the same information as US_TPCDFR1_A1 and, as such, currently only flags those whose OINCFARM components of INCFARM are top coded. Based on the INCFARM recode description, it is possible to combine both topcode flags to ensure all topcode information is included for INCFARM, however we have not confirmed that a combined topcode flag would differ from the information provided by TINCFARM. The documentation on the website is being updated to more clearly reflect the relationships between these variables. In addition, the IPUMS CPS team is planning on adding a topcode flag for INCFARM that incorporates both the topcodes for OINCFARM and INCLONGJ.