In 1987, people in the USSR could retire with pension at 55 (female) and 60 (male) while receiving 50% of their wages at a at minimum. Meanwhile, in USA the average retirement age was 62-67 and the average (not median) retiree household in the USA could expect $48k/yr which comes out to 65% of the 74k average (not median) household income in 2016:
https://www.ilo.org/public/libdoc/ilo/1994/94B09_66_englp2.pdf
https://www.cbsnews.com/news/could-you-get-by-on-the-average-americans-retirement-income/
GDP took off after socialism was established and then collapsed with the reintroduction of capitalism: