Step 1: The variable hlc0120_v1 is converted into Euro by divisor 1.95583 (not adjusted for inflation) for the years 1998 to 2001 and subsequently integrated into the harmonized variable hlc0120_h. Step 2: The variable hlc0120_h is replaced by the variable hlc0120_v2 for the years 2002 to 2014 and 2022. Step 3: The variable hlc0120_h is replaced with 0 for the years 2015 to 2020, if hlc0120_v3 does not apply to the person asked and hlc0120_v4 does not apply to the person asked. Step 4: The variable hlc0120_h is replaced with -5 for the years 2015 to 2020, if hlc0120_v3 is not included in that version of the questionnaire and hlc0120_v4 is not included in that version of the questionnaire. Step 5: The variable hlc0120_h is replaced with -3 for the years 2015 to 2020, if hlc0120_v3 is -3 or hlc0120_v4 is -3. Step 6: The variable hlc0120_h is replaced with -1 for the years 2015 to 2020, if hlc0120_v3 is -1 and hlc0120_v4 is -1. Step 7: The variable hlc0120_h is replaced by the variable hlc0120_v4 for the years 2015 to 2020, if the variables -1, -2 are 0 and hlc0120_v4 applies to the person asked. Step 8: The variable hlc0120_h is replaced by the variable hlc0120_v3 for the years 2015 to 2020, if the variables -1, -2 are 0 and hlc0120_v3 applies to the person asked. Step 9: The variable hlc0120_h is replaced with hlc0120_v3+hlc0120_v4 for the years 2015 to 2020, if hlc0120_v3 is greater than 0 and hlc0120_v4 is greater than 0.