but contribution credits have become particularly important after the introduction of defined contribution systems that strengthen the link between contributions and benefits anna d addio estimates what would happen if these credits did not exist in a number of oecd and eu countries and finds that mothers replacement rates would decrease by to percentage points on average with between and years of career interruption d addio positive effects especially for women in the lowest income groups have also been found in estimations for chile fajnzylber i anotherstudyfocused onthe united states finds that contribution credits and minimum benefits favour women in the poorest social strata while divorce benefits are mostly oriented to women in the highest income groups herd