This variable is calculated based on usual hours worked per week and weeks worked with pay in month M of year Y. M goes from 1 to 12 and represents the calendar month. Y goes from 1 to 6 and represents the number calendar year for the given SIPP panel. Months that are outside the time frame covered by an individual's SIPP panel will always be missing and out of universe. The SIPP asks for usual hours worked per week for up to two jobs. The usual hours for job 1 and job 2 are combined and then multiplied by the weeks worked with pay that month (see wkswp_Y_M). The usual hours worked SIPP variables are WS12024 and WS22024 in the 1984 panel; WS12025 and WS22125 in the 1990, 1991, 1992, and 1993 panels; and EJBHRS1 and EJBHRS2 in the 1996, 2001, 2004, and 2008 panels. Total usual hours worked per week is capped at 99 in the GSF and SSB; therefore, the cap for totalhrs_Y_M is 99 multiplied by wkswp_Y_M.