Though automatic indexation of benefits was not implemented until June 1975, movements
in the CPI-W became the guides for benefit changes subsequent to the 1972-1973 Amendments.
The 11% increase granted in June 1974 reflected an attempt to approximate the CPI change
between September 1972, the date of the last increase, and June 1974 (Myers, 1993). Between
1968 and 1972, however, Congress legislated four ad hoc benefit increases, in 1968 (13%), 1970
(15%), 1971 (10%) and 1972 (20%), that expanded real benefits dramatically. The last three of
these increases, in particular, bore no relationship to changes in the CPI-W. This contrasts with
earlier and later changes that generally reflected changes in the CPI-W.