The primary historical motivation of the EITC was to "reform" the former AFDC welfare program. There was concern that AFDC was growing too quickly: welfare rol

The primary historical motivation of the EITC was to "reform" the former AFDC welfare program. There was concern that AFDC was growing too quickly: welfare rolls increased from fewer than 1 million families in 1964, to more than 3 million in 1973. There was also concern that the AFDC program discouraged working. The EITC is structured to incentivize work, even at low wages. Another precipitating motivation was a recession in 1974 (EITC dates to 1975). https://crsreports.congress.gov/product/pdf/R/R44825/8 https://crsreports.congress.gov/product/pdf/R/R44825/8 (PDF)